So you put this title “Declination doesn’t matter!” to attract attention to your video and then you rant about what is declination for over an hour?! Well, I disagree! Declination DOES MATTER! In real life you also get really lost! And you don’t know your location every 500 meters or so! You can’t recheck your location too often in many real life situations! Then you need to find yourself and if you don’t use declination, you would be horribly wrong and make a big mistake! Of course, what you are not telling your viewers is that they need real practice and not only watching UA-cam videos! You are making the videos for subscribers and money and not to make others, ( people unknown to you), good navigators!
@@danielculpepper9258 For the UK declination doesn't matter. As here it's .0 of a degree change. Pushing up to 1-2 degree in Scotland. So unless of course you're trying to find a f*ing pebble, it has no real bearing (ba dum tis). The point here is that declination depends on your location in the world. Which is a very valid point as have many comments bellow highlighted. As well as the effect the map has on it. Finally, no one becomes a good navigator from UA-cam videos. Not once did the video say such a thing, calm down.
You are the FIRST person who has correctly explained that there are THREE norths, and that grid north is NOT the same as true north. Well done you. 9 out of 10 UA-cam sites purporting to teach compass navigation use these two terms (true north and grid north) interchangeably as if they mean the same thing. And they don't. Where I live in New Zealand, the declination from grid north to magnetic north is 21 degrees E. The declination between true north and magnetic north is 24 degrees E. If I follow grid north to visit Santa Claus, I will be many miles off by the time I get there.
Good points you have made and for sure when mag north is say 12 deg East where I am in Melbourne Australia we cant ignore it. Even more so, when the landscape is featureless for a lot of the aussie bush. A good compass with sighting mirror like the Suunto MC2G makes it a lot easier to shoot bearings. Cheers
Dumb question: do you navigate by the Magnetic North Pole or the Magnetic South Pole? Would they be different numbers? This could get complicated quickly...
@@PatrickKQ4HBD Always by magnetic north pole. And we have to use southern hemisphere compass, as the magnetic field comes up out of the ground, so we have to have north needle weighted heavier than the south, which is opposite of USA. If we dont have a southern compass, we have to take a USA compass and magnetise the needle backwards, then we use white as north and red as south, this is so we have the weighting on the south, so that when the compass is level it balances.
Watched all the way through. Well presented, very natural. Put me at ease re declination. I love navigating but from one trip to the next I've forgotten what I have learnt but now I can forget about declination and concentrate on other more important aspects. Thank you Humble Trekker.
It may not matter much, but since it's so easy to compensate for, I can't see any reason to ignore it. Why not aim for precision, and then if you're a little off, so be it, but you won't be as far off as if you ignore declination. It's easy enough to plan a route around poor terrain anyway, and if you are very good at precise land navigation, it's much easier to trust your more complicated pre-planned routing. A lot of the problems you describe come down to poor technique. Aim for perfection! You won't quite get there, but if you at least try you'll get a lot closer in the long run, especially with practice.
I see the points in his discussion on declination not being overly concerned with. More concerned about his not training people in the utilization of tools like implimenting back-stops or bearing off, and what to do when someone reaches tbese points.
It’s 12 west where I am so I’d be utterly fu*ked if I followed the advice in this video. I’d say that if the magnetic declination is any greater than + or - 3° and you are traveling more than a few miles or Kilometers, you need to do the calculations or you can really end up off course. You already have a deviation if 2 to 3 degrees even if you do the calculations simply due to the margin of inaccuracy in most compasses, so you can get off course by quite a lot if you ignore declination. It must be nice for people living near the atomic line
Exactly. In the terrain I see in this video, there are trees, brush, rocks, and hills. You can't go it a straight line for 100 yards and probably not for 100 feet.
Great explanation and very practical for the land navigation. In real situation this absolutely reasonable and practicable. We got your main point on the subject. Great one. 5stars.... Cheers..
Good explanation of practical ground movement. You only have to look at a footpath on an ordinance survey map to see the pathways. Also see a sheep track across a field. it wanders. Human beings do not like travelling in a straight line.
Very good material. Concise explanation and right conclusions. In fact, it would be possible to go in the right direction, indicated by the compass, also by dodging, choosing a better way, but only if you fixed a point lying on our azimuth and kept an eye on it or... keep him in mind - in situation if only we could find this point, even if it disappeared from our sight for a while, for example in a grove. When using a compass, it is also worth looking at the topography of the terrain, comparing it with the map. This allows you to correct the position, move in the right direction. In general, the map is the basis, I use the compass rather in the field, where the destination is not visible (e.g. in the forest) and it is impossible to determine it thanks to the map alone. Greetings from Poland.
What I use for underwater navigation works just as well for me on land. I leapfrog from landmark to landmark on fixed objects along my chosen route. In bad visibility or thick brush it helps to have a partner who moves ahead of me at my direction and then stops and waits for me to join him and then we take another bearing and so on. If I come to an obstacle it avoid it by taking right angles around it till I’m back to my original line. Having a tall visible fixed object that I can re take my bearing helps or I use a pace counter.
You are right for common navigation just trust the compass as it is. Most people do not know that the slight variation over one mile is only eight inches per mile squared. All good land surveyors know this is true and you can fact-check this. Here is why any given east-to-west line will follow a curve, but all north and south lines are straight. These days they call it declination and claim it moves but the truth is all east-to-west lines follow a curved line of eight inches per mile squared and that my friend is the truth. The surveyors in America found this error way back in the early days when surveying across the United States. If you look at a map of the United States you will find the curve at the most northern border. They wanted a straight line but the compasses led them on the curved line.
DON'T FORGET: The magnetic poles are moving. The NORTH magnetic pole, which has been in Northern Canada for hundreds of years, has left Canada and is crossing the Arctic Ocean heading for Siberia. If the direction does not change significantly, it is heading for the Indian Ocean after passing through Russia. Be sure to check with the US Geological Survey (USGS) for the current declaration for your location.
"Declination east, compass least." This means magnetic reading is a lower number than true. So if the map says 111 degrees for a bearing, the magnetic (compass) reading will be less (least) by the number of those degrees. "Declination west, compass best" These means the compass (magnetic) reading will be "better" or higher than the map (grid/true north) so if the declination is 17 degrees west, and the map tells you that the direction to take is 111 degrees, then the compass reading will be higher, so add the 17 degrees to the 111 azimuth, for a bearing on the compass of 128 degrees.
Where I walk the magnetic variation is a third to half a degree & getting smaller over the next couple of years. Magnetic North is moving East, slowly but surely according to the British Geological Survey.
Overall good points and good explanation. Especially the bit about west magnetic declination being given as negative degrees (because when you look up magnetic declination online it assumes you are taking a compass azimuth reading to the map, and the amount of west magnetic declination would be subtracted from the compass reading by adding a negative number). A topic that many people seem to have difficulty understanding why west magnetic declination is listed as say - 9˚. However, I would say the only time you can completely ignore magnetic declination is when you are not using a map with the compass, and are only using the compass to keep track of the directions and distances you walk. without reference to a map. But as a practical matter in practice, when using map and compass together, I would agree if mag declination is only ~ 5˚, most of the time mag declination can be ignored. Heck the degree ring on many compasses are only divided into 5˚ divisions. You can only estimate to a couple of degrees in between the marks. Positioning the edge of the base plate on the left or right side of a pencil dot on the map will change the measured bearing by close to 5˚, too. Most good quality base plate compasses are only accurate to 2˚~2.5˚, and can only be sighted to a landmark with about 5˚ accuracy, by most people, using good sighting technique. At best only very slightly more accurately. Probably a little more accurately if using a lensatic or prismatic compass, I have found mirror sighting compasses only slightly more accurate than a base plate compass due to parallax reading the needle alignment in the tilted mirror. Thus as a practical matter, as you pointed out, magnetic declination can mostly be ignored over short distances if mag. declination is only ~ 5˚ +/- a couple of degrees. That supports your opinion that magnetic declination can, most of time, be ignored. However, in dense fog or heavy snowfall conditions, or trying to find a geocache that is difficult to find without precise navigation to its location, adjusting for magnetic declination would, I think, be important to take into account. Errors in azimuth and impossibility to walk laser straight lines also shows why deliberate azimuth off set to a destination target, walking to a handrail & following it to the desired destination and short distances to check points, are practical necessary compass navigation techniques to use. [as an aside - afaik - only the Silva 54 6400 360, Silva 55 6400 360 or the Francis Barker M73 navigation type compasses are accurate to 0.5˚ with degree scales marked with 1˚ divisions. Only some specialty sighting compasses or geographers pocket transits rival that resolution] One can calculate how far off course you will be per degree off accurate bearing (azimuth) by thinking of a circle with a radius = the distance. Calculate the circumference. Then divide it by 360˚. Example: 1 mile = 5280ft. Circumference = 2 * r * pi = 2(5280)pi = 33,175.2 ft. --> 33,175.2/360˚ = 92.2ft/1˚. If ignoring a 5˚ magnetic declination at 1 mile you could be off course by 5 * 92.2ft = 460.8 ft or 153.6 yards. Unless looking for something very small, that's often close enough. I just use a thumb rule of ; 1mile / 100 ft / 1˚, for easy math, which would indicate I could be up to 500ft off course if ignoring a 5˚ magnetic declination, fairly close to the more accurate 461ft. calculated error . . 5˚ off at 5 miles =~ 5˚ * 5miles * 100 ft = 2,500 ft, just under 1/2 mile. Aiming for a point on a road (handrail ) that is 1/2 mile east of where you left your car is a practical navigation method. A similar metric thumb rule would be 1km / 1˚ / 20 meters (rounded up from 17.45 meters). 5˚ off to a distance of 5km (=~ 1 mile) would be 500 meters off target, 5 km * 5˚ * 20 m, fairly close to the actual calculated error of 436.2 meters. But easier math. For correct magnetic declination adjustment. I use an acronym and a phrase of my own creation. I probably recall it more reliably because I dreamed it up myself. WAvES, = West Add v East Subtract. Think magnetic waves. With the phrase -- The Map WAvES to the Compass, and the Compass WAvES back. (WAvES back means backwards ( reverse the math operation), West Add becomes West Subtract, & East Subtract becomes East Add. Meaning, for example, if hiking in an area with magnetic declination of 10˚ west. A grid azimuth measured on the map of 100˚ to a desired target --> the Map WAvES to the Compass, = West Add 10˚ to the 100˚ and set 110˚ on the compass. Or if local magnetic declination is 12˚ east. If on the map you measure an azimuth of 100˚, Map WAvES to compass, East Subtract 12˚, set on the compass 100 - 12 = 88˚. Or if walking a trail, and you want to determine your position, and with the compass read an azimuth (bearing) of 120˚ to a cell tower or distant road junction. "The Compass WAvES back(wards), = East Subtracts becomes East ADD, = 120˚ + 12˚ = 132˚ grid azimuth to be measured on the map. To find your location on the trail within a few degrees of accuracy. It's better to be a physicist than a mathematician. From an old joke about the two professions, both men - when they are given the problem, Can you reach the most beautiful woman in the world across the room IF you can only approach her by taking steps that halves the remaining distance to her? The mathematician says he can never reach her. The physicists says he can get close enough. He's the more practical fellow. Assuming compass land navigation with a standard available compass is only accurate to about 5˚ is a practical thing, I think, too. Anyway, I enjoy many of your videos. Find them informative & practical.
If you're navigating you're using a map so grid north is really the true and only north that you care about. What I do is take a sharpie, which wipes off with alcohol, and write T = M + 17 on my compass mirror. That 17E is the grid declination for my area and my maps. When you're in the field and pull out your compass the worst thing you want to have happen is to be off by 34 degrees because you screwed up some arithmetic.
Grid Magnetic Angle does matter and not accounting for it can get you killed under certain conditions. Magnetic declination where I live can be 19 degrees.
Very good presentation, but you made this is much more complicated then it really is. In the military all we subject tracked or added was magnetic to grid and grid to magnetic. And it we had to stamp the correct box. If correct practices applied it was super accurate. You had to be because a couple meters away could be the wrong box to stamp
First off a very good video and explanations. Also factually correct. But I don’t agree with forgetting about declination. I was in the armoured corps so I was not concerned with following bearings but more with travelling longish distances and then asking where are we now, exactly? The first thing we ALWAYS did was orientate the map which is get the map pointing at grid north. Then start reading the ground. In areas where the difference can be 20 degrees this makes a very big difference. You may not worry about the 87m over the 1km example given but picking out on the map which feature it is you are looking at makes a huge difference. Before doing anything ORIENTATE YOUR MAP.
1 degree off your magnetic dec will through you off course about 52metres every KM travelled. so yes, it is important if your travelling more then 1KM...
I basically disagree with the point of ignoring declination. What he is really talking about is to navigate by using terrain observation correlation techniques rather than navigation purely by compass alone. With sufficient map study and visual terrain clues, the compass is for general drecdtion finding only. However, unlike his idea of iignoring declination, it is possible to be more accurate than he implies. A general rule of thumb for the math is your cross track error will be approximately one part in 60 of the overall distance traveled for every degree of compass error for relatively small angle errors (say less than 10 degrees). If you really understand what the declination diagram on the map is telling you, there is no reason to try to remember any silly word mnemonic, which is too often easily mixed up and applied the wrong way, resulting in double the declination adjustment error in the wrong direction. Look at the declination diagram, each line is just a reference angle, the zero line from where an azimuth angle begins. Make your body into a dec diagram. point your arms to match the diagram. Say you have east declination as in his example. Stand with your outstretched left arm representing true north (standing randomly, no need to point in the actual TN direction). Then your right arm would represent magnetic north of the dec diagram, pointing slightly to the right of your left arm, just as the dec diagram shows. Now imagine an object in the first quadrant off to your right (this works regardless of which quadrant the object is really in). If converting from magnetic to true or vice versa, ask yourself which is the larger/smaller angle, that from your magnetic reference pointing right arm, or that from your true north pointing left arm? In his 5 degree example, the angle from true to the object is larger than that from mag to the object. So the true azimuth as measured on the map is 5 degrees larger than mag az as measured on the compass. Mag az as measured by the compss (being a smaller angle) is 5 degrees less than true az on the map. For west declination, reverse your arms, point right arm to imagined TN, left to MN, it all works just the same.
Great thinking. Your brain works the same as mine. It's much better to understand what's happening with the angles between the target and MN and TN, and how changing from the map to magnetic will increase or decrease that angle. I used to remember the phrases, but not anymore as they are flawed, as many countries created them to work with the declination in their country.
It takes less than 1 minute to add or subtract the Magnetic Declination or set it to the compass if your compass has an adjustable declination. Why on earth would you not want to incorporate magnetic declination. There is also many other factors that can lead a persons bearings / azimuth to be off. Inclination (or the use of the wrong compass), deviation and of course declination that could be high, like 20 degrees. And then misunderstanding the isogonic chart with westerly and easterly and adding or subtracting incorrectly. As well as forgetting to calculate or calculating incorrectly the change in the magnetic declination for the annual change. Also the initial direct compass and grid bearings my already be out by numerous degrees. And people maybe in unfamiliar territory. Add all this together when bush bashing or in open country and people could end up in a world of hurt. Some people that would hear your message, won't be as experienced as yourself, and would simply say to others, "I heard that you can just not worry about the magnetic declination"! I would advise strong caution for teaching this and would side on the side of teaching people how to incorporate magnetic declination with all of the other items above to help increase peoples accuracy. Yes it takes more effort and time, but the gained skills are worth it. You explained a lot of other good stuff that will help people, so thumbs up for that. I would think that not calculating in the magnetic declination etc, would be good, if it were in a controlled environment where people were just learning the basics. Prior to learning declination etc.
well thank you for explanation but... unless Im much mistaken it works only if I know where I am on the map so in case of transferring data from map to the actual walking I need my position on the map and position of the target, likewise I need to know where I am if I taking bearing holding a compass in my hand and shifting data on the map so in this case I also need to know where I am. What if I have no clue where I am and all I have just target ON the map? I need to fix my position somehow, pinpoint or locate myself first.. and that is a whole another story. Thank You !
If you have a map and a compass and you don’t know where you are on the map. You use triangulation to locate yourself. Find at least two visible landmarks that you can identify on the map. For example a high mountain or a radio mast. It must be visible from your location and you can recognize it on your map. Take a bearing from your location to each of these two landmarks. Transfer the bearing onto your map by drawing two lines on the map. These two lines will cross. The point they cross is where you are on the map.
@@verysurvival Im sorry to trouble you again but... would you mind telling what if my compass is not set for declination (I dont know if such compasses exist), i.e. there is no such option to pre-adjust it for that. When I take bearing either to the physical landmark or the landmark on the paper map, when should add or subtract declination? I mean... once Ive located myself , I found my point B to go towards, I ve drawn the line, I put the red in the shed (the needle on the red line) by rotating my body, now I have red arrow pointing the direction I should be heading. And noow.. can I account for the declination now? Im asking purely because Im not sure if each compass has this inbuilt capacity to adjust it (set and forget it) prior to any actual work.
Coniferous Forests hi, if you are going to adjust for declination you need to do for everything. Or ignore it all the time and just figure it is good enough . If the compass doesn’t have the adjustment that is settable then you need to do it manually at each step
@@verysurvival I appreciate the information. And this is the last one (honestly). Would it be sufficient to navigate in the wilderness just by knowing these 2 skills : how to get from point a to point b (i.e. from map to the physical world). And how to triangulate (from landmarks to map). I cant think of anything else. Am I wrong?
it means your declination is between 1 degree and 13 minutes and 1 degree and 12 minutes West, there can be local variations over the coverage of the map the map or they are accounting for a change over time so they are giving you a span. But in practical terms your declination is so small you can ignore it. because just by ignoring you would be max 1 degree out, and no one walks with one degree precision. there are 60 minutes in a degree, so it is like 1.2 degree in decimal. imagine 60 lines between the degree lines on a compass, one of those imaginary lines is a minute! ;-)
Don't think I will ever get my head around using a compass to navigate, it's soo long winded, and I've always found they are very unreliable even when you have 3 to hand, guess ime stuck with relying on the GPS on a mobile,, unless I ever meet somebody that can properly walk me through the proper ability of using compass, otherwise I will watch many of these videos and still I never get any idea of what or how to use one.
You're completely wrong about how compounding errors work, and it kind of undermines a lot of your other points. Having other potential sources of error makes it *much more* important to compensate for declination - as (if you assume that other errors can add up to 5 degrees, as you suggest) instead of being 100m off at 1km, you could be 200m off. Yes, it *could* cancel out and put you where you need to be, but you have absolutely no way of knowing that, because that's how errors work. They're unpredictable. All that said, depending on the terrain and visibility, being even 100m off at 1km could completely fuck you if you're unlucky. It hardly takes any work to make the correct for declination, and it could save your arse by cutting the potential error in your reading in half (or even more, if you're declination is greater than 5 degrees), so I don't see why you wouldn't just do it automatically once you understood how to
23 years in the military and it matters, if your trying to find a hide an op a ford even a small bridge and your almost 300 meter out you could be behind enemy lines and well and truly F##ked and the fact that you may well be walking at night we’ll need I say more. Also if you don’t want to walk over or through a patch of ground you take a bearing across it to a landmark then walk around till your lined up with that landmark again. Simple in daylight not so much in the dark.
This is crazy talk, walking 10 meters in a straight line looking down at a compass is impossible. The idea you can navigate at night with only a compass towards a ford that is being held by enemy forces is crazy 😜 talk
@@verysurvival I’ve navigated by a compass bearing at night more times than I can remember. How the hell else did you think we did it. Most of our patrols where after dark o’clock. We could do this because we often practiced Night navigation exercises. Seriously do you think soldiers only move during daylight 😂😂😂
How many times did you have to stand up & sit down while explaining the 5deg 87m difference? Make me feel tired just watching a Video, let alone going for an actual hike to test out your theories. Seriously great vid though.
Isn't one of the reasons magnetic North is not the same as true north is because of the tilt of the Earth? Since the magnetic pole of the Earth is not vertical due to the Earth having a tilt and thus we need to compensate for it.
If we live on a turning ball in a void then so called "True north" does not exist. Who is to say what the most northern part of a ball is ? North relating to Maps is the top, who is to say what the "top" of a ball is ? What universal point of reference is being used ? It is just a man made story not related to the magnetism of compasses. Why do we not know what compasses actually point to ? If we live on a flat plane then true north would represent the dead centre, assuming the plane is indeed circular.
North can be anywhere.It is only an agreed datum point from which is used to reference from. It just so happens that western navigation has agreed where it is for a thousand years. So it is very useful
@@verysurvival Ok an agreed point of reference but why would they put that cold icy place where no body goes as the focal point ? In all the places of the world ?
I like this video, I will use it to teach scouts about declination, HOWEVER, in the Northwest USA our declination is 20-22 degrees. If you are ignoring declination here, you will be 1 mile off your line after just 3.2 miles. So know your area that you are hiking.
I agree this is a good video and quite useful for teaching. However, Magnetic North has been moving very fast over the last 10-20 years (earthsky.org/earth/magnetic-north-rapid-drift-blobs-flux) . So for Portland Oregon, declination is now about 15.4°. Here is a link to a NOAA calculator (www.ngdc.noaa.gov/geomag/calculators/magcalc.shtml?useFullSite=true). I hope that this is useful. I enjoyed scouting too! It taught me a lot about the world and how to figure things out.
It does matter. People have died 50 feet from shelter. You should therefore always calculate for declination if possible, and try to be as accurate as possible.
There are many reports of this kind but sadly, compass land navigation does not provide that level of accuracy. And you have to take that in consideration. People died 50 feet from shelter because of improper preparation, terrain knowledge and navigating in poor visibility. If you are susceptible to fall in that kind of situation, the best item for land navigation is a GPS.
@@schiaucugabriel6202 Compass Navigation DOES provide you with enough information and accuracy to find the major landmarks, rivers, or roads, mountain peaks, lakes, gullies, unless you are in a blizzard with zero visability, but then as you said, GPS is the best. Compass use in the right hands is fairly reliable and can get you where you need to go, if you understand it and use it right. Databyter
@@cacadores3955 Go take correct magnetic north bearing in poor visibility on the Bucegi plateau where is no landmarks miles around and you are dead. If you get lost in the blizzard there, the magnetic north is as useful as a bicycle to a fish. That"s why people are dead yards away from shelter. Doh!
Yes good video, good explanation and I suppose it's all down to preference and your own personal way of navigating. Personally for me if the difference is more than 2 degrees then you need to take adjustments into account. I do a lot of scrambling and go from ridge to ridge often in poor vis and 2 degrees is the max for me. I would definitely recommend a compass where you can pre set the declination for your area but learning to move from map to compass and vice versa is an essential like learning your times table, its there if you need it. Any young guns out there thinking gps is the answer, yes it is good but if your scrambling through rocks and gulleys your gps will multi map and ping you duff locations, big buildings in cities sometimes do this plus if your on the go for a few days you don't need batteries👍
Yep, those 2º over 300m is 10 metres error. Going into a ridge crossing with 10 metres safe pass with unexpected fog or whiteout, where you can't wait it out... indeed, can become a serious problem fast.
Declination doesn’t matter for land navigation in wooded areas in practical applications... every NCO in the Army and Marine Corps just said “hold my beer” hahahaha!!!
Declination is so easy to adjust for. Why would you deliberately introduce an additional 1 - 22 degrees of error into an already imperfect navigation method? If you're triangulating your position on a map based on distant landmarks and a magnetic compass you would be way off plotting your location. It's just good habit to take everything into account every time even though it's not a perfect system. 300 meters out is enough to miss your tennis court several times over.
As I said in the video my recommendation is that it can be ignored in most cases when it is under 10 degrees only. So from 10-22 degrees is not on the table to be ignored. when it is below 3 degrees it is probably below the average persons precision anyway so that leaves a grey area from 3-10 degrees that is debatable. My main point is that it is perfectly possible to accurately navigate in the sub 10 degree range without considering declination in most circumstances
Excellent video on the practicality of declination. I used to be involved in the creation of such maps and you did a great job of explaining the Norths (there's also geodetic North but lets not get in to that). One thing viewers might question is why the difference between grid N, and True N and why it has to be adjusted for (though not in a practical way as you have demonstrated) so showing that the grid is a series of perpendicular "square" lines evenly spaced along a baseline (like graph paper) and when you slap that grid on a curved surface (the Earth) you'll see that the further N or S you go from that baseline the more divergence there is from the grid to the True lines longitude. Grids are perfect for the coordinate systems we use. From the grid you can get and calculate coordinates on our maps. lat/Lon is good for navigation. Great job on the video!
Great video! Your knowledge of orienteering is very impressive. Unfortunately, most people that get lost in the woods are not as knowledgable as you. Why worry about the map being obsolete if your compass is preset to the proper declination? Most people never need a compass as long as they stay on a marked trail. When you are bushwhacking or lost is when you need a good compass. If someone is lost, tired and not as seasoned as someone like you wouldn't it best to keep it simple? Instead of adding and subtracting in your head while distressed wouldn't it be prudent and more practical to orient the map and compass and triangulate while forming a cocked hat to determine location? Once your approximate location is determined you can then plan a route to get back to the trail and on to your destination. If not, a person could stay lost and compound there already mounting problems. I live in Western Montana, The AOD is 13.5 degrees positive (east). Even if it was less than 10 degrees it would still be important. The area of the Rocky mountains I live in are rugged and have several peaks. If you are bushwhacking in my neck of the woods it is easy to get lost unless you are proficient at orienteering and a seasoned hiker. Many visible peaks are approximately the same altitude or present a false summit. Again, on a marked trail who cares? In a survival situation, I believe in keeping it simple. The best way to avoid getting lost is to stay found! Again, TY for the video and applying common sense.
Nice to see a UK guy talk about kilometers ;). And a very informative video. I do teach declination, inclination and most of all the human mistake factor. Most students use electronic devices now until batteries run out. I usually say, different continent, different compass if you are in terrain where a compass that points accurate is really necessary so in remote areas with few landmarks. Even a button compass that points in the wrong direction but in a constant matter can still be used to prevent you from walking in circles. Because walking in circles is no myth. That's what we do naturally.
2° between grid north and geographic north + 5° magnetic declination + 2° compass magnetic and mechanical tolerence + 2° reading and adjusting approximation, if we are unlucky and one approximation doesn't compensate the other one might end up 10° off while taking magnetic declination into consideration keeps us in a more acceptable range of error. Bearings of one or several km on a straight line are not unusual for people canoeing huge lakes in canada, scandinavia and so.
I suppose if you are walking in approx 1km legs in between known waypoints and correcting your bearing each time, you could get away without correcting for declination. But that can come back to bite if you are trying to locate yourself on a map and your only good known landmarks are in the 2-4km range (mountain tops, hill tops, large manmade structures, etc). Because that error will also be present and will cause pretty significant error in your position triangulation when plotted on your map. Why that matters significantly is because if you are using features for handrails, you might very well be thinking you are just east of a handrail (when if fact you are actually just west of the handrail) and you will work west thinking the handrail is surely coming up. And it never does. Or worse, you keep going west, and you find a similar handrail feature and misinterpret it as the one you were looking for and you end up following the wrong handrail for a couple/few kilometers. Last weekend we had a difficult time finding our camp (with manmade structures and vehicles) from only 300 meters away. So errors of .5 km would make me pretty uncomfortable. Statistically, many people who get lost and end up spending a night(s) in the woods unprepared are less than 1500m from their parked vehicle. To be fair, I live in an area with a 12.5 declination. So I can't really ignore it. But with the triangulation error I mentioned, even 5 degrees could be problematic (depending on the distance to visible landmarks).
I’m getting back into hiking having not used a map and compass in 15 years since I was in the scouts! This video and your channel is super helpful in refreshing my memory on loads of things. Nice one mate!
On Ordnance Survey maps the variation / declination of Magnetic north is given from Grid North and True North variation is also given from Grid North. I only ever need to know the variation from Grid North to Magentic north when taking bearing from either land or from a map. Its interesting that the Grid datum for OS maps is 2 degrees west (true Origin) and recently the change of magnetic variation has crossed from West to East start at Langton Matravers on the Dorset coast in November 2022 and is slowly moving north leaving the English Coast at Berwick upon Tweed during August 2025
Thanks for info ... Just wanted to mention some compasses have a screw that you can adjust the declination on the compass itself and not have to calculate add or subtract the declination manually
Good explanation - Terrible application! The whole damn reason we consider declination is to remove error. Your meandering along a path in a given direction is what is known as "cross track error" my friend. Now, in the UK where a forest is really an open park and you cant go more than 2 miles in any direction without stumbling into a town or a pub, yes..... who gives a shit about being accurate? it does not really matter! Just stop and ask somebody along the way or flag down a car passing on a nearby road for directions. Your whole island is an urban area or semi rural land ..... straight line in any direction and you will hit a village, road, or again.... a pub. I am in Canada - where meandering along a bearing and not paying attention to accuracy and cross track error will end you in the shit big time. 5 kilometers along a path and being hundreds of meters off track in our dense thick woods will have your head spinning when the map suddenly does not make sense to you in a literal sea of green bush. So yes, we do actually attempt to move in a straight line in the bush to remove error - to the extent of hitting the edge of a pond and trying to note the point on the other side to move around to and start back on the path of travel. You must take out the cross track error! When multiplied over hundreds or thousands of meters of travel in dense bush with no obvious landmarks, and no pub to stop at - you can end up kilometers off track to either side of your planned path and no clue where you are if you're not paying attention to accuracy when you play in our back yard. Navigation has an expectation of accuracy for a reason mate - ask any of the people I have had to rescue over the last 30 years who were lost in our woods. They all tell the same story of confusion and not being able to figure out where they were because the map started "making no sense" to the route they thought they were travelling. They had significantly veered left or right off track (compounded cross track error) and ended up in some combination of lost, cold, panicked or hurt. I hope people stumbling across this take home the message that accuracy is VERY important in thick bush with no landmarks ..... and no pubs along the way! Equally important is the ability to accurately pace and record your distance travelled along the route so you have more of what we call "positive information" to help figure it out should things not make sense anymore and your GPS cell phone app is not working because the battery just died. (hope you brought a map) Just saying.
In land navigation, the declination become an issue in Northen Canada and Northen Russia where it can go up to 50°. Less but still, in South Africa or New Zeeland, where a proper calibration of magnetic declination is more than necessary.
In New England we're not that far from the magnetic north pole, so declination is substantial. It's over -14 degrees where I live, and more than -15 in Maine. But here straight line navigation is nearly impossible due to either land being owned, or natural barriers.
True Virgins Make Dull Company: Add Whisky True north +/- Variation Magnetic north +/- declination Compass north Add for west, subtract for east [when moving down the list, opposite when moving back up the list]
Even without a compass, just head east to the trail. (of course you must know the area on your head if you don't have map) What's the distance, 2-3 miles? you won't miss a north south path in two miles. What time was it?...I assume later in day so sun is southwest/ west... regardless...put the sun at your back / right shoulder and walk east, the sun sets in west, is south at noon and east in the morning. Even with clouds a knife blade tip on your fingernail form make a sundial, it casts a shadow and reveals the source of light even in fog. You can also use a watch (not digital) Using the hour hand, 12 o'clock mark and sun it will give geometry lines that you can determine your direction. if you don't have anything, put a stick in ground and put a mark on the ground every hour. (daylight) this will form a circular dial with a bit more precise increments than just N.E.W.S. The marks are opposite the sun as the sun travels across the south. Go online and research this "using watch for direction finding"
I'm at 12 degrees west declination. I will NOT be ignoring declination. If I did this I would be 208 meters off at 1 kilometer. That could be 208 meters of heavy woods, a lake, a giant hill, different elevation, etc. You seem to think this is good advice for "most". "Most" people do not live in 5 to -5 declination. In America that represents about 1/5 of the land mass. Your advice is BAD for 80% of Americans. And similar for other peoples in the world who live in a large geographic country. I understand in reality we don't navigate in a straight line. That is why we adjust for declination so we can be as accurate as possible. You're in a bubble.
Ive learned how to navigate by watching youtube, Ive watched many land nav vids on here, yours is one of the best, I wanted to brush up a bit and came across your video,, thanks
I'd agree if the video made it clear from the onset that's its whether people would usually need to use it. The same applies to the use of a compass. Most of the time, in a landscape with identifiable features, a decent map and a pair of eyes is ample. I'd still carry a compass and knowledge and consideration of declination. Every 2º in a 300m distance is 10 metres error. On a mountain top or ridge, where conditions go from blue sky to for or even a whiteout, direction and keeping up with distance travelled now could be the difference between being safe and falling off a cliff. Imagine a ridge has a safe width of 10 metres, any more than those 2º becomes a serious risk of going into a crevice. Similar if the need arises to go through a forest or any open moorland fog because of the lack of identifiable features now. Without considering declination, the person or group might end up on the wrong side of an unsurpassable obstacle, and the hours lost means travelling at night or an unplanned night stay without adequate kit, greatly increasing risk. So those 5º can matter a lot. In Finland or Toronto, not being in the poles, declination is 9º and 10º. Its also important to know the error built in can double because of small navigation errors or path chosen. Making even more important the use of techniques like aiming off. It could be argued that since manufacturers acceptable compass error is 2 degrees, you can ignore any 2º. You can say that in most of the UK, today, the declination is between 0 and 1º, so totally disregard. However, disregarding is not the same as not mattering. It mattered and it was accounted for. From that point of view it matters a great deal and thus I find the video title very misleading, even dangerous advice.
I would argue that if you're in a hilly or mountainous area with a good topo, why should you need a compass or a pace count, to begin with? I was varsity orienteering in high school. I almost never even took the time to look at my compass and didn't really bother with counting my paces. I looked at the topo and the terrain, then said to my group, "we need to head towards that high/low area, then go towards that landmark, follow the valley/ ridge and we should hit our next checkpoint should be right in the middle". We always made much better time than the compass/pace count nerds. When I set up courses, my maps were typically more accurate, as well. I'd use the compass and my purse count from the landmark for the last potion to be sure, but I was using terrain to get to the general location. Of course, this was a mountainous area and we knew our starting point. If we hadn't been in northern New Mexico but, instead travelling through White Sands, the compass would be important. I'd be watching my compass the whole time, making damned sure I was keeping an accurate pace count. The few meets we went to on flat desert, I did exactly that and beat the kids who were talking bearings every few minutes because they'd invariably travel off course, having to figure out how far off they were. When we didn't hit our checkpoint (and yes, we challenged a few), GPS showed the maps to be wrong.
There is also the map itself. It is important to learn to read the map itself, so that if your compass bearing is a bit wrong you know where you are. Also you might be better off taking shorter legs if you are not that good at reading the map. It is very easy to get lost in the forest even if you have as many compasses as humanly possible.
For me, call me old school but I prefer a compass, map and notebook. GPS is a wonderful and accurate tool, however, GPS is not without its limitations which are satellite signals and battery life. Lose any of those two and you will wish you had a good compass and map. A compass will not let you down, but you do need to learn how to use it.
Finally a declination explanation I was able to retain. (They all make sense to a greater or lesser degree, while you’re watching them. The key for me has been difficulty in recalling them once the video stops.)
If I am traveling on land, and I have a compass with no adjustment for mag declination, and am doing an "out and back" hunting route, I see no need for compute declination or variation at all. The compass will remain true and get me back to my starting point...
In the north of Norway with 14°E declination, above the tree-line in the winter, with rolling snow-clad hills, not accounting for declination will get You lost real quick. You can guess that there are lakes in the low points, but You cant identify them by shape. You explained it well, but missing by 100m is enough if visibility is 50m. Considering You only really need to follow a compass if visibility is poor, and poor visibility is usually accompanied by bad weather and a need for shelter. I'd say You need to learn to take declination into account.
If visibility is poor you cannot use a compass for accurate navigation since using a compass for accurate navigation depends on repeatedly sighting the compass to a distant landmark. So you are wrong. You actually prove why point is correct, if you try and follow a compass in bad visibility over 10 meters say you will already be off track by along way so don’t do it
I watched this video because of the title. Perhaps it should have been titled 'Compass Declination: Why it matters and when you need to use it' as that is what you demonstrated. There are many areas across the globe where there is a significant Grid Magnetic Angle and where even over short distances it must be accounted for. In my experience I'd only really consider disregarding GMA if it was 3 degrees or less (but that's a personal prefererence) and only over very short legs. Having said that the majority of the time you will require to carry out compass work will be in poor visibility or at night. If navigating in a whiteout in the Scottish Highlands I'd be trying to maintain as accurate a bearing as possible, as even a small variation can be dangerous. Many years ago I trained on Swedish maps which were extremely interesting as those sheets were of an area where on one side of the map the GMA was positive and the other half was negative! So the old adage of Grid to Mag add, Mag to Grid get rid was reversed on the other half of the map. I still navigate using a Mils compass and it was very simple to calculate error as 1 mil = 1 metre at 1km. There are roughly 17 mils to the degree so every degree of error works out at around 17m over a kilometre. With a good sighting compass you can get some really accurate results,though as you say not laser accurate. For those looking for a book on the subject I can recommend 'The Ultimate Navigation Manual' by Lyle Brotherton.
Excellent video... I have watch three others that got me more confused about declination and this one was my saviour. Thank you, enough info that you understand but not enough that your left wondering what hit you.
You need to take this video down because it will or has already gotten someone killed in land navigation. YES!! It does matter about declination no matter what terrain you’re in. People have gotten lost within 100m off safety and in North America it ranges as wide as 20 degrees declination. What is your background to feed people this BS? Mine is former military who aced land navigation. Take this video down.
So you put this title “Declination doesn’t matter!” to attract attention to your video and then you rant about what is declination for 27 minutes?! Well, I disagree! Declination DOES MATTER! In real life, you also get really lost! And you don’t know your location every 500 paces or so! You can’t recheck your location too often in many real life situations! Then you need to find yourself and if you don’t use declination, you would be simply horribly wrong and make a big mistake! Declination may be only 1-2 degrees in the UK but it could be 15 or even 22 in the North West US so it’s really important. But of course, what you are not telling your viewers is that they need real practice and not only watching UA-cam videos! You are making the videos for subscribers and money and not to make others, (people unknown to you), good navigators!
This disregard for declination is frankly irresponsible. It is absolutely essential if you are up a mountain in Scotland and the fog descends or snow/ rain reduces visibility to virtual zero. Unfortunately every year we have many fatalities in the Highlands, mostly amateurs but occasionally experts succumb to the terrain. So please know how to map read properly before enjoying our mountains.🙂
I was taught Land Nav by the USArmy and they were very anal about adjusting for declination at all times...but when you are calling in air strikes you need that degree of accuracy I suppose lol. BUT... I wasted SO munch time on regular "walk from here to there" land nav dealing with lensatic compasses, protractors and declination math. If I only had a Silva back in my Ft. Dix Land Nav course lol! But the Army (back then at least) forced you to do it because the land navigation tests required you to find a small "Crazy Ivan" target with a code on it in the middle of the woods over multiple kilometer distances. Knowing what I know now. I'd have used a Silva and ignored declination till I was a few hundred meters from my target. Then do a resection with declination to get my exact(ish) location, then shoot that last bearing with declination to get me to my point.
There are some really faulty assumptions at work here, and some sketchy shortcuts. He talks about not being able to walk in a straight line, and that builds in error. That's absolutely true. Why, then, would you deliberately choose to compound the error by ignoring declination? The bit about "you'll always be able to see a landmark" assumes a lot, and obviously doesn't come from a place of familiarity with North American forests. You can travel a long time without seeing the sky or horizon. In places like Oklahoma where there are plenty of forest and no peaks to speak of, good luck finding that mythical landmark. You do you, dude, but I'll continue to compensate for declination.
Great explanations on the three north versions. I concur with other commenters on your excellent coverage of this. However, as to ignoring declination I think it’s dangerous to say you can ignore it or it doesn’t matter. Rather it would be much safer to say you should be aware of what it is so you know which side of your intended target you are aiming for that you will end up. So if you have an easterly declination, you would want to know that so that if you get to the intended distance and you can’t find the object you’re looking for you would know to start looking westerly from your current location. Even if it’s a river you hit or a road etc you would need to know that in the case of an easterly declination that you would be east of your intended meeting point on the road so that you are to head west to arrive at your desired “meeting point”. However, here in Australia and you need to get to a water point eg a windmill pump or a soak or watering point that is on the map you would not want to be ‘ignoring’ the local declination when you could easily be hiking 10km - 23 kms to get there. The error after 5kms here could totally mean the difference between NOT finding that windmill and hence your desired water source. In bush locations you will miss a windmill even it it’s less than 300m away. So my point is readers / viewers - interpret this information carefully for your particular location because I can assure you - here in Australia if you’re out bush and intending to travel to a specific site out bush ON FOOT you do not want to be ignoring declination. The consequences on a 30 -45 Deg C. Day could be very dire. In the least it could just be the embarrassment of having to be rescued because you end up getting lost. Aussies familiar with our outback will know what I am talking about. A significant amount of our country does not afford the pleasures of lots of items to sight or garner a bearing from once you leave the high ground. So perhaps in some countries or regions within some countries (including Australia) perhaps you might be able to ignore it because of the existence of plenty of secondary locator items to help you work out where you are but in some regions (especially outback Australia) you can’t afford to ignore the effects on your navigation of local area declination. I’m not knocking HT and this great video presentation. Just wanting to make sure you do apply a little common sense when interpreting this message and how to apply it to your intended hike / walk location.
@@YouGruff on a mountain ridge, on an unexpected fog, knowing the its 20 metres wide, only 10 metres are safe, but you can't see it and you can't wait it out. Whether the person decides its important to factor it or if it can be disregarded its their decision. Hence, it mattered and was accounted for. Its the same as for the use of a compass. Many times, with lots of features, compass stays in the bag. I wouldn't say it wouldn't matter.
Exactly. The presenter is from England: we have mist, white-outs and heavy rain that can just roll in from the sea with no warning. The question is, why does he really think risking getting lost is BETTER than half a second twisting a compass ring by the magnetic off-set number? So dumb!
@@YouGruff 10°? On the moors or in the mountains, 1.5° off can get you killed. What really is the argument for NOT taking a ten-second magnetic bearing? Don't get it.
Excellent explanation and I agree with most of your points, however it seems to be largely due to coincidence, that the Zero declination lines happen to run right through the middle of the US and Europe right now, which is another question in and of itself...
Yes, all this talk about declination confuses me! And that rhyme is the same whether your east or west....the way we were taught was that an East variation is a minus (east us least) and a west variation is positive ( west is best,) to if you'd magnetic variation is 5e, and you are going from a mag bearing of say 150 to a grid, it is 150 - -5, which is 155.... If the mag variation was 10w, going from mag to grid it would be 150- 10 =140....the beauty of this method is you do the same thing regardless of whether variation is east or west. ..it also works in reverse for converting from grid to mag...
Isn't it easier to apply the magnetic declination to the map, by correcting tbe grid line + / - degrees. And drawing parallel lines to it? Thus, we will have updated the map to its current magnetic declination. Cheers.
That’s another way of doing it. But requires the preparation of sitting down with a ruler and drawing all the new lines. It makes things easy once it’s done
YEAP , Naaa , in NZ we have over 20 degrees , and thats WAY too much to ignore , so NO from me , and in dead reckoning , no , I want accuracy , when in close country or featureless terrain , need to be spot on .
In general in the internet, it needs to be made much clearer that, in the uk at least, it’s the magnetic variation angle rather than declination we use to navigate ie we look at grid north, not true north. In Fort William right now the declination is 2 degrees but the variation angle is as close to 0 it makes no difference. That actually can make a huge difference, especially if you’re navigating between gullies in a white out
This comment is nonsense magetic variation and magnetic declination are two names for the same thing. My source is Encylopedia Brittanica. www.britannica.com/technology/variation-compass
If you're standing down under, (Australia) holding a compass in a level position, isn't it pointing to outer space?To point in a northern direction shouldn't it point in a vertical direction as the north is up over ?
Nope. You need a south hemisphere compass and a compass needle actually aligns itself to the lines of magnetic field at the place you are standing. It doesn’t actually point at a spot in the north. But those lines if your were to walk along them would eventually arrive at that point, like following a winding path way
the best explanations I've seen yet.
So you put this title “Declination doesn’t matter!” to attract attention to your video and then you rant about what is declination for over an hour?!
Well, I disagree! Declination DOES MATTER! In real life you also get really lost! And you don’t know your location every 500 meters or so! You can’t recheck your location too often in many real life situations!
Then you need to find yourself and if you don’t use declination, you would be horribly wrong and make a big mistake!
Of course, what you are not telling your viewers is that they need real practice and not only watching UA-cam videos! You are making the videos for subscribers and money and not to make others, ( people unknown to you), good navigators!
@@danielculpepper9258 For the UK declination doesn't matter. As here it's .0 of a degree change. Pushing up to 1-2 degree in Scotland. So unless of course you're trying to find a f*ing pebble, it has no real bearing (ba dum tis). The point here is that declination depends on your location in the world. Which is a very valid point as have many comments bellow highlighted. As well as the effect the map has on it. Finally, no one becomes a good navigator from UA-cam videos. Not once did the video say such a thing, calm down.
thank you Very Survival to explain the declination so good. Its really the best explainiton i see on youtube and internet. Helped me out.
You are the FIRST person who has correctly explained that there are THREE norths, and that grid north is NOT the same as true north. Well done you. 9 out of 10 UA-cam sites purporting to teach compass navigation use these two terms (true north and grid north) interchangeably as if they mean the same thing. And they don't. Where I live in New Zealand, the declination from grid north to magnetic north is 21 degrees E. The declination between true north and magnetic north is 24 degrees E. If I follow grid north to visit Santa Claus, I will be many miles off by the time I get there.
Check out Corporal's Corner. His land navigation video also discussed the three norths.
fakecubed I agree corporal kelly and this tutorial are the most clear and accurate navigation tutorials on UA-cam 👍🏻
Good points you have made and for sure when mag north is say 12 deg East where I am in Melbourne Australia we cant ignore it. Even more so, when the landscape is featureless for a lot of the aussie bush. A good compass with sighting mirror like the Suunto MC2G makes it a lot easier to shoot bearings.
Cheers
Dumb question: do you navigate by the Magnetic North Pole or the Magnetic South Pole? Would they be different numbers? This could get complicated quickly...
@@PatrickKQ4HBD Always by magnetic north pole. And we have to use southern hemisphere compass, as the magnetic field comes up out of the ground, so we have to have north needle weighted heavier than the south, which is opposite of USA. If we dont have a southern compass, we have to take a USA compass and magnetise the needle backwards, then we use white as north and red as south, this is so we have the weighting on the south, so that when the compass is level it balances.
Watched all the way through. Well presented, very natural. Put me at ease re declination. I love navigating but from one trip to the next I've forgotten what I have learnt but now I can forget about declination and concentrate on other more important aspects. Thank you Humble Trekker.
Welcome mate
It may not matter much, but since it's so easy to compensate for, I can't see any reason to ignore it. Why not aim for precision, and then if you're a little off, so be it, but you won't be as far off as if you ignore declination. It's easy enough to plan a route around poor terrain anyway, and if you are very good at precise land navigation, it's much easier to trust your more complicated pre-planned routing. A lot of the problems you describe come down to poor technique. Aim for perfection! You won't quite get there, but if you at least try you'll get a lot closer in the long run, especially with practice.
fair comment
Yes. The argument, 'it's better to be inaccurate and accept a 260m error when you don't need to' is a little mad.
I see the points in his discussion on declination not being overly concerned with. More concerned about his not training people in the utilization of tools like implimenting back-stops or bearing off, and what to do when someone reaches tbese points.
Where I live, it's 11°E, double your problems. In the bush, you'd be right out if you didn't account
It’s 12 west where I am so I’d be utterly fu*ked if I followed the advice in this video. I’d say that if the magnetic declination is any greater than + or - 3° and you are traveling more than a few miles or Kilometers, you need to do the calculations or you can really end up off course. You already have a deviation if 2 to 3 degrees even if you do the calculations simply due to the margin of inaccuracy in most compasses, so you can get off course by quite a lot if you ignore declination. It must be nice for people living near the atomic line
Even I could follow you here, good to know.
many thanks... now i understand
This is how I’ve always done it. I have got lost a few times in my life, but never using a map and compass and I’ve always done it this way.
Exactly. In the terrain I see in this video, there are trees, brush, rocks, and hills. You can't go it a straight line for 100 yards and probably not for 100 feet.
word
Great explanation and very practical for the land navigation. In real situation this absolutely reasonable and practicable. We got your main point on the subject. Great one. 5stars.... Cheers..
Glad it was helpful!
This is exactly how we trained in the military for the bush war in South Africa. 10 out of 10
cheers
Good explanation of practical ground movement. You only have to look at a footpath on an ordinance survey map to see the pathways. Also see a sheep track across a field. it wanders. Human beings do not like travelling in a straight line.
great mate
Very good material. Concise explanation and right conclusions. In fact, it would be possible to go in the right direction, indicated by the compass, also by dodging, choosing a better way, but only if you fixed a point lying on our azimuth and kept an eye on it or... keep him in mind - in situation if only we could find this point, even if it disappeared from our sight for a while, for example in a grove.
When using a compass, it is also worth looking at the topography of the terrain, comparing it with the map. This allows you to correct the position, move in the right direction. In general, the map is the basis, I use the compass rather in the field, where the destination is not visible (e.g. in the forest) and it is impossible to determine it thanks to the map alone. Greetings from Poland.
Cheers and beers
What I use for underwater navigation works just as well for me on land. I leapfrog from landmark to landmark on fixed objects along my chosen route. In bad visibility or thick brush it helps to have a partner who moves ahead of me at my direction and then stops and waits for me to join him and then we take another bearing and so on. If I come to an obstacle it avoid it by taking right angles around it till I’m back to my original line. Having a tall visible fixed object that I can re take my bearing helps or I use a pace counter.
interesting to compare to diving, cool
This is a fantastic explanation. Subscribed and look forward to more!
Awesome, thank you!
You are right for common navigation just trust the compass as it is. Most people do not know that the slight variation over one mile is only eight inches per mile squared. All good land surveyors know this is true and you can fact-check this. Here is why any given east-to-west line will follow a curve, but all north and south lines are straight. These days they call it declination and claim it moves but the truth is all east-to-west lines follow a curved line of eight inches per mile squared and that my friend is the truth. The surveyors in America found this error way back in the early days when surveying across the United States. If you look at a map of the United States you will find the curve at the most northern border. They wanted a straight line but the compasses led them on the curved line.
Hi I think the video is very informative and well presented. Will use in presentation for cadets to aid there use of a compass and route cards.Thanks
Thanks .
DON'T FORGET:
The magnetic poles are moving. The NORTH magnetic pole, which has been in Northern Canada for hundreds of years, has left Canada and is crossing the Arctic Ocean heading for Siberia. If the direction does not change significantly, it is heading for the Indian Ocean after passing through Russia.
Be sure to check with the US Geological Survey (USGS) for the current declaration for your location.
"Declination east, compass least."
This means magnetic reading is a lower number than true. So if the map says 111 degrees for a bearing, the magnetic (compass) reading will be less (least) by the number of those degrees.
"Declination west, compass best" These means the compass (magnetic) reading will be "better" or higher than the map (grid/true north) so if the declination is 17 degrees west, and the map tells you that the direction to take is 111 degrees, then the compass reading will be higher, so add the 17 degrees to the 111 azimuth, for a bearing on the compass of 128 degrees.
Where I walk the magnetic variation is a third to half a degree & getting smaller over the next couple of years. Magnetic North is moving East, slowly but surely according to the British Geological Survey.
Overall good points and good explanation. Especially the bit about west magnetic declination being given as negative degrees (because when you look up magnetic declination online it assumes you are taking a compass azimuth reading to the map, and the amount of west magnetic declination would be subtracted from the compass reading by adding a negative number). A topic that many people seem to have difficulty understanding why west magnetic declination is listed as say - 9˚.
However, I would say the only time you can completely ignore magnetic declination is when you are not using a map with the compass, and are only using the compass to keep track of the directions and distances you walk. without reference to a map.
But as a practical matter in practice, when using map and compass together, I would agree if mag declination is only ~ 5˚, most of the time mag declination can be ignored. Heck the degree ring on many compasses are only divided into 5˚ divisions. You can only estimate to a couple of degrees in between the marks. Positioning the edge of the base plate on the left or right side of a pencil dot on the map will change the measured bearing by close to 5˚, too.
Most good quality base plate compasses are only accurate to 2˚~2.5˚, and can only be sighted to a landmark with about 5˚ accuracy, by most people, using good sighting technique. At best only very slightly more accurately. Probably a little more accurately if using a lensatic or prismatic compass, I have found mirror sighting compasses only slightly more accurate than a base plate compass due to parallax reading the needle alignment in the tilted mirror.
Thus as a practical matter, as you pointed out, magnetic declination can mostly be ignored over short distances if mag. declination is only ~ 5˚ +/- a couple of degrees. That supports your opinion that magnetic declination can, most of time, be ignored.
However, in dense fog or heavy snowfall conditions, or trying to find a geocache that is difficult to find without precise navigation to its location, adjusting for magnetic declination would, I think, be important to take into account. Errors in azimuth and impossibility to walk laser straight lines also shows why deliberate azimuth off set to a destination target, walking to a handrail & following it to the desired destination and short distances to check points, are practical necessary compass navigation techniques to use.
[as an aside - afaik - only the Silva 54 6400 360, Silva 55 6400 360 or the Francis Barker M73 navigation type compasses are accurate to 0.5˚ with degree scales marked with 1˚ divisions. Only some specialty sighting compasses or geographers pocket transits rival that resolution]
One can calculate how far off course you will be per degree off accurate bearing (azimuth) by thinking of a circle with a radius = the distance. Calculate the circumference. Then divide it by 360˚.
Example: 1 mile = 5280ft. Circumference = 2 * r * pi = 2(5280)pi = 33,175.2 ft. --> 33,175.2/360˚ = 92.2ft/1˚. If ignoring a 5˚ magnetic declination at 1 mile you could be off course by 5 * 92.2ft = 460.8 ft or 153.6 yards. Unless looking for something very small, that's often close enough.
I just use a thumb rule of ; 1mile / 100 ft / 1˚, for easy math, which would indicate I could be up to 500ft off course if ignoring a 5˚ magnetic declination, fairly close to the more accurate 461ft. calculated error . . 5˚ off at 5 miles =~ 5˚ * 5miles * 100 ft = 2,500 ft, just under 1/2 mile. Aiming for a point on a road (handrail ) that is 1/2 mile east of where you left your car is a practical navigation method.
A similar metric thumb rule would be 1km / 1˚ / 20 meters (rounded up from 17.45 meters). 5˚ off to a distance of 5km (=~ 1 mile) would be 500 meters off target, 5 km * 5˚ * 20 m, fairly close to the actual calculated error of 436.2 meters. But easier math.
For correct magnetic declination adjustment. I use an acronym and a phrase of my own creation. I probably recall it more reliably because I dreamed it up myself.
WAvES, = West Add v East Subtract. Think magnetic waves. With the phrase -- The Map WAvES to the Compass, and the Compass WAvES back. (WAvES back means backwards ( reverse the math operation), West Add becomes West Subtract, & East Subtract becomes East Add.
Meaning, for example, if hiking in an area with magnetic declination of 10˚ west. A grid azimuth measured on the map of 100˚ to a desired target --> the Map WAvES to the Compass, = West Add 10˚ to the 100˚ and set 110˚ on the compass.
Or if local magnetic declination is 12˚ east. If on the map you measure an azimuth of 100˚, Map WAvES to compass, East Subtract 12˚, set on the compass 100 - 12 = 88˚. Or if walking a trail, and you want to determine your position, and with the compass read an azimuth (bearing) of 120˚ to a cell tower or distant road junction. "The Compass WAvES back(wards), = East Subtracts becomes East ADD, = 120˚ + 12˚ = 132˚ grid azimuth to be measured on the map. To find your location on the trail within a few degrees of accuracy.
It's better to be a physicist than a mathematician. From an old joke about the two professions, both men - when they are given the problem, Can you reach the most beautiful woman in the world across the room IF you can only approach her by taking steps that halves the remaining distance to her? The mathematician says he can never reach her. The physicists says he can get close enough. He's the more practical fellow. Assuming compass land navigation with a standard available compass is only accurate to about 5˚ is a practical thing, I think, too.
Anyway, I enjoy many of your videos. Find them informative & practical.
What about Celestial North?
Also, the UK is how many miles wide? Ignore declination at your own risk in the western US.
Very useful. Thanks!
Excellent knowledge.
Perfect explanation.
Glad you think so!
Awesome explanation ! How many meters per degree of declination error is there in a kilometer?
17.5 meters
@@verysurvival Thanks
If you're navigating you're using a map so grid north is really the true and only north that you care about. What I do is take a sharpie, which wipes off with alcohol, and write T = M + 17 on my compass mirror. That 17E is the grid declination for my area and my maps. When you're in the field and pull out your compass the worst thing you want to have happen is to be off by 34 degrees because you screwed up some arithmetic.
Maybe when holding your compass at your belly you're not that accurate but using a lensatic compass you can be quite consistent.
Grid Magnetic Angle does matter and not accounting for it can get you killed under certain conditions. Magnetic declination where I live can be 19 degrees.
Very good presentation, but you made this is much more complicated then it really is. In the military all we subject tracked or added was magnetic to grid and grid to magnetic. And it we had to stamp the correct box. If correct practices applied it was super accurate. You had to be because a couple meters away could be the wrong box to stamp
First off a very good video and explanations. Also factually correct. But I don’t agree with forgetting about declination.
I was in the armoured corps so I was not concerned with following bearings but more with travelling longish distances and then asking where are we now, exactly? The first thing we ALWAYS did was orientate the map which is get the map pointing at grid north. Then start reading the ground. In areas where the difference can be 20 degrees this makes a very big difference.
You may not worry about the 87m over the 1km example given but picking out on the map which feature it is you are looking at makes a huge difference.
Before doing anything ORIENTATE YOUR MAP.
cheers mate
Thanks
1 degree off your magnetic dec will through you off course about 52metres every KM travelled. so yes, it is important if your travelling more then 1KM...
I basically disagree with the point of ignoring declination. What he is really talking about is to navigate by using terrain observation correlation techniques rather than navigation purely by compass alone. With sufficient map study and visual terrain clues, the compass is for general drecdtion finding only. However, unlike his idea of iignoring declination, it is possible to be more accurate than he implies. A general rule of thumb for the math is your cross track error will be approximately one part in 60 of the overall distance traveled for every degree of compass error for relatively small angle errors (say less than 10 degrees).
If you really understand what the declination diagram on the map is telling you, there is no reason to try to remember any silly word mnemonic, which is too often easily mixed up and applied the wrong way, resulting in double the declination adjustment error in the wrong direction. Look at the declination diagram, each line is just a reference angle, the zero line from where an azimuth angle begins. Make your body into a dec diagram. point your arms to match the diagram. Say you have east declination as in his example. Stand with your outstretched left arm representing true north (standing randomly, no need to point in the actual TN direction). Then your right arm would represent magnetic north of the dec diagram, pointing slightly to the right of your left arm, just as the dec diagram shows. Now imagine an object in the first quadrant off to your right (this works regardless of which quadrant the object is really in). If converting from magnetic to true or vice versa, ask yourself which is the larger/smaller angle, that from your magnetic reference pointing right arm, or that from your true north pointing left arm? In his 5 degree example, the angle from true to the object is larger than that from mag to the object. So the true azimuth as measured on the map is 5 degrees larger than mag az as measured on the compass. Mag az as measured by the compss (being a smaller angle) is 5 degrees less than true az on the map. For west declination, reverse your arms, point right arm to imagined TN, left to MN, it all works just the same.
Great thinking. Your brain works the same as mine. It's much better to understand what's happening with the angles between the target and MN and TN, and how changing from the map to magnetic will increase or decrease that angle. I used to remember the phrases, but not anymore as they are flawed, as many countries created them to work with the declination in their country.
It takes less than 1 minute to add or subtract the Magnetic Declination or set it to the compass if your compass has an adjustable declination. Why on earth would you not want to incorporate magnetic declination. There is also many other factors that can lead a persons bearings / azimuth to be off. Inclination (or the use of the wrong compass), deviation and of course declination that could be high, like 20 degrees. And then misunderstanding the isogonic chart with westerly and easterly and adding or subtracting incorrectly. As well as forgetting to calculate or calculating incorrectly the change in the magnetic declination for the annual change. Also the initial direct compass and grid bearings my already be out by numerous degrees. And people maybe in unfamiliar territory.
Add all this together when bush bashing or in open country and people could end up in a world of hurt. Some people that would hear your message, won't be as experienced as yourself, and would simply say to others, "I heard that you can just not worry about the magnetic declination"!
I would advise strong caution for teaching this and would side on the side of teaching people how to incorporate magnetic declination with all of the other items above to help increase peoples accuracy. Yes it takes more effort and time, but the gained skills are worth it.
You explained a lot of other good stuff that will help people, so thumbs up for that. I would think that not calculating in the magnetic declination etc, would be good, if it were in a controlled environment where people were just learning the basics. Prior to learning declination etc.
I got lost
well thank you for explanation but... unless Im much mistaken it works only if I know where I am on the map so in case of transferring data from map to the actual walking I need my position on the map and position of the target, likewise I need to know where I am if I taking bearing holding a compass in my hand and shifting data on the map so in this case I also need to know where I am. What if I have no clue where I am and all I have just target ON the map? I need to fix my position somehow, pinpoint or locate myself first.. and that is a whole another story. Thank You !
If you have a map and a compass and you don’t know where you are on the map. You use triangulation to locate yourself. Find at least two visible landmarks that you can identify on the map. For example a high mountain or a radio mast. It must be visible from your location and you can recognize it on your map. Take a bearing from your location to each of these two landmarks. Transfer the bearing onto your map by drawing two lines on the map. These two lines will cross. The point they cross is where you are on the map.
@@verysurvival allrighty ... I highly appreciate your input. thank you for the prompt reply. It was fast.
@@verysurvival Im sorry to trouble you again but... would you mind telling what if my compass is not set for declination (I dont know if such compasses exist), i.e. there is no such option to pre-adjust it for that. When I take bearing either to the physical landmark or the landmark on the paper map, when should add or subtract declination? I mean... once Ive located myself , I found my point B to go towards, I ve drawn the line, I put the red in the shed (the needle on the red line) by rotating my body, now I have red arrow pointing the direction I should be heading. And noow.. can I account for the declination now? Im asking purely because Im not sure if each compass has this inbuilt capacity to adjust it (set and forget it) prior to any actual work.
Coniferous Forests hi, if you are going to adjust for declination you need to do for everything. Or ignore it all the time and just figure it is good enough . If the compass doesn’t have the adjustment that is settable then you need to do it manually at each step
@@verysurvival I appreciate the information. And this is the last one (honestly). Would it be sufficient to navigate in the wilderness just by knowing these 2 skills : how to get from point a to point b (i.e. from map to the physical world). And how to triangulate (from landmarks to map). I cant think of anything else. Am I wrong?
Right buddy i looked at my map and it says that magnetic north is 1°13 and 1°12 west of grid north. What the hell does that mean? Im in uk too
it means your declination is between 1 degree and 13 minutes and 1 degree and 12 minutes West, there can be local variations over the coverage of the map the map or they are accounting for a change over time so they are giving you a span. But in practical terms your declination is so small you can ignore it. because just by ignoring you would be max 1 degree out, and no one walks with one degree precision.
there are 60 minutes in a degree, so it is like 1.2 degree in decimal. imagine 60 lines between the degree lines on a compass, one of those imaginary lines is a minute! ;-)
@@verysurvival cool thanks for the reply. Its mind bogglin to me but thankfully in uk its no big deal.
my brain hurts, very informative
Lol it was a bit different to my normal vids
True N 2,5 GRid 5 Magnetic = 7,5 Degree and 7,5 Degree x 24 hours = 180 Degree Flat Earth ?
Don't think I will ever get my head around using a compass to navigate, it's soo long winded, and I've always found they are very unreliable even when you have 3 to hand, guess ime stuck with relying on the GPS on a mobile,, unless I ever meet somebody that can properly walk me through the proper ability of using compass, otherwise I will watch many of these videos and still I never get any idea of what or how to use one.
Great 👍
You're completely wrong about how compounding errors work, and it kind of undermines a lot of your other points. Having other potential sources of error makes it *much more* important to compensate for declination - as (if you assume that other errors can add up to 5 degrees, as you suggest) instead of being 100m off at 1km, you could be 200m off. Yes, it *could* cancel out and put you where you need to be, but you have absolutely no way of knowing that, because that's how errors work. They're unpredictable.
All that said, depending on the terrain and visibility, being even 100m off at 1km could completely fuck you if you're unlucky. It hardly takes any work to make the correct for declination, and it could save your arse by cutting the potential error in your reading in half (or even more, if you're declination is greater than 5 degrees), so I don't see why you wouldn't just do it automatically once you understood how to
23 years in the military and it matters, if your trying to find a hide an op a ford even a small bridge and your almost 300 meter out you could be behind enemy lines and well and truly F##ked and the fact that you may well be walking at night we’ll need I say more. Also if you don’t want to walk over or through a patch of ground you take a bearing across it to a landmark then walk around till your lined up with that landmark again. Simple in daylight not so much in the dark.
This is crazy talk, walking 10 meters in a straight line looking down at a compass is impossible. The idea you can navigate at night with only a compass towards a ford that is being held by enemy forces is crazy 😜 talk
@@verysurvival I’ve navigated by a compass bearing at night more times than I can remember. How the hell else did you think we did it. Most of our patrols where after dark o’clock. We could do this because we often practiced Night navigation exercises. Seriously do you think soldiers only move during daylight 😂😂😂
How many times did you have to stand up & sit down while explaining the 5deg 87m difference? Make me feel tired just watching a Video, let alone going for an actual hike to test out your theories. Seriously great vid though.
haha . did i do alot of moving. cant remember was a long time ago ;-)
Isn't one of the reasons magnetic North is not the same as true north is because of the tilt of the Earth? Since the magnetic pole of the Earth is not vertical due to the Earth having a tilt and thus we need to compensate for it.
No that is not the reason. Magnetic north is caused by the hot molten metals flowing around in the earth. The tilt is nothing to do with it really
If we live on a turning ball in a void then so called "True north" does not exist. Who is to say what the most northern part of a ball is ? North relating to Maps is the top, who is to say what the "top" of a ball is ? What universal point of reference is being used ? It is just a man made story not related to the magnetism of compasses.
Why do we not know what compasses actually point to ?
If we live on a flat plane then true north would represent the dead centre, assuming the plane is indeed circular.
North can be anywhere.It is only an agreed datum point from which is used to reference from. It just so happens that western navigation has agreed where it is for a thousand years. So it is very useful
@@verysurvival Ok an agreed point of reference but why would they put that cold icy place where no body goes as the focal point ? In all the places of the world ?
DAMIT this means it's so much easier if you are a FLAT EARTHER!
DUH
Please look at the camera. Look at us, your audience, and not yourself. Pet peeve of mine.
I like this video, I will use it to teach scouts about declination, HOWEVER, in the Northwest USA our declination is 20-22 degrees. If you are ignoring declination here, you will be 1 mile off your line after just 3.2 miles. So know your area that you are hiking.
I agree this is a good video and quite useful for teaching. However, Magnetic North has been moving very fast over the last 10-20 years (earthsky.org/earth/magnetic-north-rapid-drift-blobs-flux) . So for Portland Oregon, declination is now about 15.4°. Here is a link to a NOAA calculator (www.ngdc.noaa.gov/geomag/calculators/magcalc.shtml?useFullSite=true).
I hope that this is useful. I enjoyed scouting too! It taught me a lot about the world and how to figure things out.
Same here in New Zealand
It does matter. People have died 50 feet from shelter. You should therefore always calculate for declination if possible, and try to be as accurate as possible.
Exactly.
There are many reports of this kind but sadly, compass land navigation does not provide that level of accuracy. And you have to take that in consideration. People died 50 feet from shelter because of improper preparation, terrain knowledge and navigating in poor visibility. If you are susceptible to fall in that kind of situation, the best item for land navigation is a GPS.
@@schiaucugabriel6202 Compass Navigation DOES provide you with enough information and accuracy to find the major landmarks, rivers, or roads, mountain peaks, lakes, gullies, unless you are in a blizzard with zero visability, but then as you said, GPS is the best. Compass use in the right hands is fairly reliable and can get you where you need to go, if you understand it and use it right. Databyter
@@schiaucugabriel6202 But if you take a correct magnetic north bearing you CAN navigate in poor visibility. That's the whole point. Doh!
@@cacadores3955 Go take correct magnetic north bearing in poor visibility on the Bucegi plateau where is no landmarks miles around and you are dead. If you get lost in the blizzard there, the magnetic north is as useful as a bicycle to a fish. That"s why people are dead yards away from shelter. Doh!
Yes good video, good explanation and I suppose it's all down to preference and your own personal way of navigating. Personally for me
if the difference is more than 2 degrees then you need to take adjustments into account. I do a lot of scrambling and go from ridge to ridge often in poor vis and 2 degrees is the max for me. I would definitely recommend a compass where you can pre set the declination for your area but learning to move from map to compass and vice versa is an essential like learning your times table, its there if you need it. Any young guns out there thinking gps is the answer, yes it is good but if your scrambling through rocks and gulleys your gps will multi map and ping you duff locations, big buildings in cities sometimes do this plus if your on the go for a few days you don't need batteries👍
Yep, those 2º over 300m is 10 metres error. Going into a ridge crossing with 10 metres safe pass with unexpected fog or whiteout, where you can't wait it out... indeed, can become a serious problem fast.
Yep. How long does it take to adjust for magnetic north? Half a second? To ignore it in mountains is dangerous stupidity.
Declination doesn’t matter for land navigation in wooded areas in practical applications... every NCO in the Army and Marine Corps just said “hold my beer” hahahaha!!!
Declination is so easy to adjust for. Why would you deliberately introduce an additional 1 - 22 degrees of error into an already imperfect navigation method? If you're triangulating your position on a map based on distant landmarks and a magnetic compass you would be way off plotting your location. It's just good habit to take everything into account every time even though it's not a perfect system. 300 meters out is enough to miss your tennis court several times over.
As I said in the video my recommendation is that it can be ignored in most cases when it is under 10 degrees only. So from 10-22 degrees is not on the table to be ignored. when it is below 3 degrees it is probably below the average persons precision anyway so that leaves a grey area from 3-10 degrees that is debatable. My main point is that it is perfectly possible to accurately navigate in the sub 10 degree range without considering declination in most circumstances
One of the best explanations I've seen yet. Thank you % Godspeed.
Just subscribed.
Thanks a lot I appreciate the feedback
Excellent video on the practicality of declination. I used to be involved in the creation of such maps and you did a great job of explaining the Norths (there's also geodetic North but lets not get in to that). One thing viewers might question is why the difference between grid N, and True N and why it has to be adjusted for (though not in a practical way as you have demonstrated) so showing that the grid is a series of perpendicular "square" lines evenly spaced along a baseline (like graph paper) and when you slap that grid on a curved surface (the Earth) you'll see that the further N or S you go from that baseline the more divergence there is from the grid to the True lines longitude. Grids are perfect for the coordinate systems we use. From the grid you can get and calculate coordinates on our maps. lat/Lon is good for navigation. Great job on the video!
i think its subtract 5, so 158 should be 153...
Great video! Your knowledge of orienteering is very impressive. Unfortunately, most people that get lost in the woods are not as knowledgable as you. Why worry about the map being obsolete if your compass is preset to the proper declination? Most people never need a compass as long as they stay on a marked trail. When you are bushwhacking or lost is when you need a good compass. If someone is lost, tired and not as seasoned as someone like you wouldn't it best to keep it simple? Instead of adding and subtracting in your head while distressed wouldn't it be prudent and more practical to orient the map and compass and triangulate while forming a cocked hat to determine location? Once your approximate location is determined you can then plan a route to get back to the trail and on to your destination. If not, a person could stay lost and compound there already mounting problems. I live in Western Montana, The AOD is 13.5 degrees positive (east). Even if it was less than 10 degrees it would still be important. The area of the Rocky mountains I live in are rugged and have several peaks. If you are bushwhacking in my neck of the woods it is easy to get lost unless you are proficient at orienteering and a seasoned hiker. Many visible peaks are approximately the same altitude or present a false summit. Again, on a marked trail who cares? In a survival situation, I believe in keeping it simple. The best way to avoid getting lost is to stay found! Again, TY for the video and applying common sense.
thankyou Eddy
Nice to see a UK guy talk about kilometers ;). And a very informative video. I do teach declination, inclination and most of all the human mistake factor. Most students use electronic devices now until batteries run out.
I usually say, different continent, different compass if you are in terrain where a compass that points accurate is really necessary so in remote areas with few landmarks.
Even a button compass that points in the wrong direction but in a constant matter can still be used to prevent you from walking in circles. Because walking in circles is no myth. That's what we do naturally.
2° between grid north and geographic north + 5° magnetic declination + 2° compass magnetic and mechanical tolerence + 2° reading and adjusting approximation, if we are unlucky and one approximation doesn't compensate the other one might end up 10° off while taking magnetic declination into consideration keeps us in a more acceptable range of error. Bearings of one or several km on a straight line are not unusual for people canoeing huge lakes in canada, scandinavia and so.
I suppose if you are walking in approx 1km legs in between known waypoints and correcting your bearing each time, you could get away without correcting for declination. But that can come back to bite if you are trying to locate yourself on a map and your only good known landmarks are in the 2-4km range (mountain tops, hill tops, large manmade structures, etc). Because that error will also be present and will cause pretty significant error in your position triangulation when plotted on your map. Why that matters significantly is because if you are using features for handrails, you might very well be thinking you are just east of a handrail (when if fact you are actually just west of the handrail) and you will work west thinking the handrail is surely coming up. And it never does. Or worse, you keep going west, and you find a similar handrail feature and misinterpret it as the one you were looking for and you end up following the wrong handrail for a couple/few kilometers. Last weekend we had a difficult time finding our camp (with manmade structures and vehicles) from only 300 meters away. So errors of .5 km would make me pretty uncomfortable. Statistically, many people who get lost and end up spending a night(s) in the woods unprepared are less than 1500m from their parked vehicle.
To be fair, I live in an area with a 12.5 declination. So I can't really ignore it. But with the triangulation error I mentioned, even 5 degrees could be problematic (depending on the distance to visible landmarks).
I’m getting back into hiking having not used a map and compass in 15 years since I was in the scouts! This video and your channel is super helpful in refreshing my memory on loads of things. Nice one mate!
awesome bro have a great time
Ignore what he says about not bothering with magnetic north. Do that and you could fall over a ravine.
On Ordnance Survey maps the variation / declination of Magnetic north is given from Grid North and True North variation is also given from Grid North. I only ever need to know the variation from Grid North to Magentic north when taking bearing from either land or from a map. Its interesting that the Grid datum for OS maps is 2 degrees west (true Origin) and recently the change of magnetic variation has crossed from West to East start at Langton Matravers on the Dorset coast in November 2022 and is slowly moving north leaving the English Coast at Berwick upon Tweed during August 2025
Thanks for info ... Just wanted to mention some compasses have a screw that you can adjust the declination on the compass itself and not have to calculate add or subtract the declination manually
Good explanation - Terrible application! The whole damn reason we consider declination is to remove error. Your meandering along a path in a given direction is what is known as "cross track error" my friend. Now, in the UK where a forest is really an open park and you cant go more than 2 miles in any direction without stumbling into a town or a pub, yes..... who gives a shit about being accurate? it does not really matter! Just stop and ask somebody along the way or flag down a car passing on a nearby road for directions. Your whole island is an urban area or semi rural land ..... straight line in any direction and you will hit a village, road, or again.... a pub. I am in Canada - where meandering along a bearing and not paying attention to accuracy and cross track error will end you in the shit big time. 5 kilometers along a path and being hundreds of meters off track in our dense thick woods will have your head spinning when the map suddenly does not make sense to you in a literal sea of green bush. So yes, we do actually attempt to move in a straight line in the bush to remove error - to the extent of hitting the edge of a pond and trying to note the point on the other side to move around to and start back on the path of travel. You must take out the cross track error! When multiplied over hundreds or thousands of meters of travel in dense bush with no obvious landmarks, and no pub to stop at - you can end up kilometers off track to either side of your planned path and no clue where you are if you're not paying attention to accuracy when you play in our back yard. Navigation has an expectation of accuracy for a reason mate - ask any of the people I have had to rescue over the last 30 years who were lost in our woods. They all tell the same story of confusion and not being able to figure out where they were because the map started "making no sense" to the route they thought they were travelling. They had significantly veered left or right off track (compounded cross track error) and ended up in some combination of lost, cold, panicked or hurt. I hope people stumbling across this take home the message that accuracy is VERY important in thick bush with no landmarks ..... and no pubs along the way! Equally important is the ability to accurately pace and record your distance travelled along the route so you have more of what we call "positive information" to help figure it out should things not make sense anymore and your GPS cell phone app is not working because the battery just died. (hope you brought a map) Just saying.
In land navigation, the declination become an issue in Northen Canada and Northen Russia where it can go up to 50°. Less but still, in South Africa or New Zeeland, where a proper calibration of magnetic declination is more than necessary.
In New England we're not that far from the magnetic north pole, so declination is substantial. It's over -14 degrees where I live, and more than -15 in Maine. But here straight line navigation is nearly impossible due to either land being owned, or natural barriers.
True Virgins Make Dull Company: Add Whisky
True north
+/- Variation
Magnetic north
+/- declination
Compass north
Add for west, subtract for east [when moving down the list, opposite when moving back up the list]
Thats a swedish map you are using. In fact its close to my home lol. Thats was unexpected 😂
Even without a compass, just head east to the trail. (of course you must know the area on your head if you don't have map)
What's the distance, 2-3 miles? you won't miss a north south path in two miles.
What time was it?...I assume later in day so sun is southwest/ west... regardless...put the sun at your back / right shoulder and walk east, the sun sets in west, is south at noon and east in the morning.
Even with clouds a knife blade tip on your fingernail form make a sundial, it casts a shadow and reveals the source of light even in fog.
You can also use a watch (not digital)
Using the hour hand, 12 o'clock mark and sun it will give geometry lines that you can determine your direction.
if you don't have anything, put a stick in ground and put a mark on the ground every hour. (daylight) this will form a circular dial with a bit more precise increments than just N.E.W.S.
The marks are opposite the sun as the sun travels across the south.
Go online and research this "using watch for direction finding"
I'm at 12 degrees west declination. I will NOT be ignoring declination. If I did this I would be 208 meters off at 1 kilometer. That could be 208 meters of heavy woods, a lake, a giant hill, different elevation, etc. You seem to think this is good advice for "most". "Most" people do not live in 5 to -5 declination. In America that represents about 1/5 of the land mass. Your advice is BAD for 80% of Americans. And similar for other peoples in the world who live in a large geographic country. I understand in reality we don't navigate in a straight line. That is why we adjust for declination so we can be as accurate as possible. You're in a bubble.
Ive learned how to navigate by watching youtube, Ive watched many land nav vids on here, yours is one of the best, I wanted to brush up a bit and came across your video,, thanks
thats cool to hear, cheers
I'd agree if the video made it clear from the onset that's its whether people would usually need to use it. The same applies to the use of a compass. Most of the time, in a landscape with identifiable features, a decent map and a pair of eyes is ample. I'd still carry a compass and knowledge and consideration of declination.
Every 2º in a 300m distance is 10 metres error. On a mountain top or ridge, where conditions go from blue sky to for or even a whiteout, direction and keeping up with distance travelled now could be the difference between being safe and falling off a cliff. Imagine a ridge has a safe width of 10 metres, any more than those 2º becomes a serious risk of going into a crevice.
Similar if the need arises to go through a forest or any open moorland fog because of the lack of identifiable features now. Without considering declination, the person or group might end up on the wrong side of an unsurpassable obstacle, and the hours lost means travelling at night or an unplanned night stay without adequate kit, greatly increasing risk.
So those 5º can matter a lot. In Finland or Toronto, not being in the poles, declination is 9º and 10º. Its also important to know the error built in can double because of small navigation errors or path chosen. Making even more important the use of techniques like aiming off.
It could be argued that since manufacturers acceptable compass error is 2 degrees, you can ignore any 2º. You can say that in most of the UK, today, the declination is between 0 and 1º, so totally disregard. However, disregarding is not the same as not mattering. It mattered and it was accounted for.
From that point of view it matters a great deal and thus I find the video title very misleading, even dangerous advice.
I would argue that if you're in a hilly or mountainous area with a good topo, why should you need a compass or a pace count, to begin with? I was varsity orienteering in high school. I almost never even took the time to look at my compass and didn't really bother with counting my paces. I looked at the topo and the terrain, then said to my group, "we need to head towards that high/low area, then go towards that landmark, follow the valley/ ridge and we should hit our next checkpoint should be right in the middle". We always made much better time than the compass/pace count nerds. When I set up courses, my maps were typically more accurate, as well. I'd use the compass and my purse count from the landmark for the last potion to be sure, but I was using terrain to get to the general location. Of course, this was a mountainous area and we knew our starting point.
If we hadn't been in northern New Mexico but, instead travelling through White Sands, the compass would be important. I'd be watching my compass the whole time, making damned sure I was keeping an accurate pace count. The few meets we went to on flat desert, I did exactly that and beat the kids who were talking bearings every few minutes because they'd invariably travel off course, having to figure out how far off they were. When we didn't hit our checkpoint (and yes, we challenged a few), GPS showed the maps to be wrong.
There is also the map itself. It is important to learn to read the map itself, so that if your compass bearing is a bit wrong you know where you are. Also you might be better off taking shorter legs if you are not that good at reading the map. It is very easy to get lost in the forest even if you have as many compasses as humanly possible.
For me, call me old school but I prefer a compass, map and notebook. GPS is a wonderful and accurate tool, however, GPS is not without its limitations which are satellite signals and battery life. Lose any of those two and you will wish you had a good compass and map. A compass will not let you down, but you do need to learn how to use it.
Finally a declination explanation I was able to retain. (They all make sense to a greater or lesser degree, while you’re watching them. The key for me has been difficulty in recalling them once the video stops.)
If I am traveling on land, and I have a compass with no adjustment for mag declination, and am doing an "out and back" hunting route, I see no need for compute declination or variation at all. The compass will remain true and get me back to my starting point...
When I was in the military we were taught the Grandma socks rule which is Grid -> Magnetic -> Subtract (Grandma’s Socks)
In the north of Norway with 14°E declination, above the tree-line in the winter, with rolling snow-clad hills, not accounting for declination will get You lost real quick. You can guess that there are lakes in the low points, but You cant identify them by shape. You explained it well, but missing by 100m is enough if visibility is 50m.
Considering You only really need to follow a compass if visibility is poor, and poor visibility is usually accompanied by bad weather and a need for shelter. I'd say You need to learn to take declination into account.
If visibility is poor you cannot use a compass for accurate navigation since using a compass for accurate navigation depends on repeatedly sighting the compass to a distant landmark. So you are wrong. You actually prove why point is correct, if you try and follow a compass in bad visibility over 10 meters say you will already be off track by along way so don’t do it
Very good vid. Here in NZ declaration is around 22 degree. very hard to ignore especially in misty weather.
Yes mate. That’s a different story
Brilliant video! Well done😊 This video helped me a lot‼️ thank you👍
Sorry, but, bad to teach this. Compensating for magnetic declination is 100% necessary to learn and use.
The towering north korea temporally force because accelerator beverly mug towards a truthful sail. cheap, fascinated graphic
I watched this video because of the title. Perhaps it should have been titled 'Compass Declination: Why it matters and when you need to use it' as that is what you demonstrated. There are many areas across the globe where there is a significant Grid Magnetic Angle and where even over short distances it must be accounted for. In my experience I'd only really consider disregarding GMA if it was 3 degrees or less (but that's a personal prefererence) and only over very short legs. Having said that the majority of the time you will require to carry out compass work will be in poor visibility or at night. If navigating in a whiteout in the Scottish Highlands I'd be trying to maintain as accurate a bearing as possible, as even a small variation can be dangerous. Many years ago I trained on Swedish maps which were extremely interesting as those sheets were of an area where on one side of the map the GMA was positive and the other half was negative! So the old adage of Grid to Mag add, Mag to Grid get rid was reversed on the other half of the map.
I still navigate using a Mils compass and it was very simple to calculate error as 1 mil = 1 metre at 1km. There are roughly 17 mils to the degree so every degree of error works out at around 17m over a kilometre. With a good sighting compass you can get some really accurate results,though as you say not laser accurate.
For those looking for a book on the subject I can recommend 'The Ultimate Navigation Manual' by Lyle Brotherton.
maybe you are right!
Looks like declination is irrelevant if you take a sight bearing and only becomes relevant if you’re moving from a map to a bearing.
Excellent video... I have watch three others that got me more confused about declination and this one was my saviour. Thank you, enough info that you understand but not enough that your left wondering what hit you.
You are absolutely right! Actually you don’t even need a compass (or a map for that matter). Just follow the traffic signs or ask a kind local...
Just never get out the Uber
You need to take this video down because it will or has already gotten someone killed in land navigation. YES!! It does matter about declination no matter what terrain you’re in. People have gotten lost within 100m off safety and in North America it ranges as wide as 20 degrees declination. What is your background to feed people this BS? Mine is former military who aced land navigation. Take this video down.
Amazing 🤩
So you put this title “Declination doesn’t matter!” to attract attention to your video and then you rant about what is declination for 27 minutes?!
Well, I disagree! Declination DOES MATTER! In real life, you also get really lost! And you don’t know your location every 500 paces or so! You can’t recheck your location too often in many real life situations!
Then you need to find yourself and if you don’t use declination, you would be simply horribly wrong and make a big mistake! Declination may be only 1-2 degrees in the UK but it could be 15 or even 22 in the North West US so it’s really important.
But of course, what you are not telling your viewers is that they need real practice and not only watching UA-cam videos! You are making the videos for subscribers and money and not to make others, (people unknown to you), good navigators!
So you missed the part of my video when I stated “don’t ignore declination if it is over 10 degrees.” You got lost just watching a UA-cam video mate
This disregard for declination is frankly irresponsible. It is absolutely essential if you are up a mountain in Scotland and the fog descends or snow/ rain reduces visibility to virtual zero. Unfortunately every year we have many fatalities in the Highlands, mostly amateurs but occasionally experts succumb to the terrain. So please know how to map read properly before enjoying our mountains.🙂
Do me a favour. Declination in Scotland is about 1 degree. You don’t know what you are talking about
I was taught Land Nav by the USArmy and they were very anal about adjusting for declination at all times...but when you are calling in air strikes you need that degree of accuracy I suppose lol. BUT... I wasted SO munch time on regular "walk from here to there" land nav dealing with lensatic compasses, protractors and declination math. If I only had a Silva back in my Ft. Dix Land Nav course lol!
But the Army (back then at least) forced you to do it because the land navigation tests required you to find a small "Crazy Ivan" target with a code on it in the middle of the woods over multiple kilometer distances. Knowing what I know now. I'd have used a Silva and ignored declination till I was a few hundred meters from my target. Then do a resection with declination to get my exact(ish) location, then shoot that last bearing with declination to get me to my point.
exactly, brilliant reflection.
There are some really faulty assumptions at work here, and some sketchy shortcuts. He talks about not being able to walk in a straight line, and that builds in error. That's absolutely true. Why, then, would you deliberately choose to compound the error by ignoring declination? The bit about "you'll always be able to see a landmark" assumes a lot, and obviously doesn't come from a place of familiarity with North American forests. You can travel a long time without seeing the sky or horizon. In places like Oklahoma where there are plenty of forest and no peaks to speak of, good luck finding that mythical landmark. You do you, dude, but I'll continue to compensate for declination.
My thoughts exactly. I'll continue to navigate the way the corporal taught me. Hasn't let me down yet.
Thank you! This one the only videos I've found that actually explains compass and map nav well.
nice to hear. take care mate
Interesting information, but I will still set my magnetic declination. :)
Great explanations on the three north versions. I concur with other commenters on your excellent coverage of this.
However, as to ignoring declination I think it’s dangerous to say you can ignore it or it doesn’t matter. Rather it would be much safer to say you should be aware of what it is so you know which side of your intended target you are aiming for that you will end up. So if you have an easterly declination, you would want to know that so that if you get to the intended distance and you can’t find the object you’re looking for you would know to start looking westerly from your current location. Even if it’s a river you hit or a road etc you would need to know that in the case of an easterly declination that you would be east of your intended meeting point on the road so that you are to head west to arrive at your desired “meeting point”. However, here in Australia and you need to get to a water point eg a windmill pump or a soak or watering point that is on the map you would not want to be ‘ignoring’ the local declination when you could easily be hiking 10km - 23 kms to get there. The error after 5kms here could totally mean the difference between NOT finding that windmill and hence your desired water source. In bush locations you will miss a windmill even it it’s less than 300m away. So my point is readers / viewers - interpret this information carefully for your particular location because I can assure you - here in Australia if you’re out bush and intending to travel to a specific site out bush ON FOOT you do not want to be ignoring declination. The consequences on a 30 -45 Deg C. Day could be very dire. In the least it could just be the embarrassment of having to be rescued because you end up getting lost. Aussies familiar with our outback will know what I am talking about. A significant amount of our country does not afford the pleasures of lots of items to sight or garner a bearing from once you leave the high ground. So perhaps in some countries or regions within some countries (including Australia) perhaps you might be able to ignore it because of the existence of plenty of secondary locator items to help you work out where you are but in some regions (especially outback Australia) you can’t afford to ignore the effects on your navigation of local area declination.
I’m not knocking HT and this great video presentation. Just wanting to make sure you do apply a little common sense when interpreting this message and how to apply it to your intended hike / walk location.
He does mention the importance of anything over 10 degrees, also the variances in readings from compass bearing and sighting to landmark etc
@@YouGruff on a mountain ridge, on an unexpected fog, knowing the its 20 metres wide, only 10 metres are safe, but you can't see it and you can't wait it out. Whether the person decides its important to factor it or if it can be disregarded its their decision. Hence, it mattered and was accounted for.
Its the same as for the use of a compass. Many times, with lots of features, compass stays in the bag. I wouldn't say it wouldn't matter.
Exactly. The presenter is from England: we have mist, white-outs and heavy rain that can just roll in from the sea with no warning. The question is, why does he really think risking getting lost is BETTER than half a second twisting a compass ring by the magnetic off-set number? So dumb!
@@YouGruff 10°? On the moors or in the mountains, 1.5° off can get you killed. What really is the argument for NOT taking a ten-second magnetic bearing? Don't get it.
Excellent explanation and I agree with most of your points, however it seems to be largely due to coincidence, that the Zero declination lines happen to run right through the middle of the US and Europe right now, which is another question in and of itself...
The also go through the middle of asia, India, South America, the Pacific Ocean , Oceania , Africa and Western Australia.
In the Army we used to call it the magnetic variation, we remebered it by the rhyme Mag to grid = get rid, or Grid to Mag= add.
Clever rhyme
Yes, all this talk about declination confuses me! And that rhyme is the same whether your east or west....the way we were taught was that an East variation is a minus (east us least) and a west variation is positive ( west is best,) to if you'd magnetic variation is 5e, and you are going from a mag bearing of say 150 to a grid, it is 150 - -5, which is 155.... If the mag variation was 10w, going from mag to grid it would be 150- 10 =140....the beauty of this method is you do the same thing regardless of whether variation is east or west. ..it also works in reverse for converting from grid to mag...
Isn't it easier to apply the magnetic declination to the map, by correcting tbe grid line + / - degrees. And drawing parallel lines to it? Thus, we will have updated the map to its current magnetic declination. Cheers.
That’s another way of doing it. But requires the preparation of sitting down with a ruler and drawing all the new lines. It makes things easy once it’s done
YEAP , Naaa , in NZ we have over 20 degrees , and thats WAY too much to ignore , so NO from me , and in dead reckoning , no , I want accuracy , when in close country or featureless terrain , need to be spot on .
I said don't ignore it over 10 degrees
In general in the internet, it needs to be made much clearer that, in the uk at least, it’s the magnetic variation angle rather than declination we use to navigate ie we look at grid north, not true north.
In Fort William right now the declination is 2 degrees but the variation angle is as close to 0 it makes no difference. That actually can make a huge difference, especially if you’re navigating between gullies in a white out
This comment is nonsense magetic variation and magnetic declination are two names for the same thing. My source is Encylopedia Brittanica. www.britannica.com/technology/variation-compass
If you're standing down under, (Australia) holding a compass in a level position, isn't it pointing to outer space?To point in a northern direction shouldn't it point in a vertical direction as the north is up over ?
Nope. You need a south hemisphere compass and a compass needle actually aligns itself to the lines of magnetic field at the place you are standing. It doesn’t actually point at a spot in the north. But those lines if your were to walk along them would eventually arrive at that point, like following a winding path way