Why Do Sailors Use Knots And Nautical Miles Instead of Kilometers?!?!?
Вставка
- Опубліковано 26 лис 2022
- In this video we describe why sailors use knots and nautical miles to navigate instead of kilometers.
Locations on the earth's surface are typically marked using degrees of latitude and longitude. Degrees are further broken down into minutes, and one nautical mile is defined as one minute of latitude, so it is very easy to calculate the distance between two points on the surface of the earth.
Airplane pilots tend to use knots and nautical miles for the exact same reason.
Disclaimer:
- This content is offered solely for your education and entertainment.
- There are no warranties, expressed or implicit, about any content or its fitness for a particular purpose.
- There are risks of injury, death, drunkenness, and financial hardship involved in sailing.
- The skipper is always responsible for the safety of their vessel and crew.
- Sailing Tips is not responsible or liable in any way for anything that happens on or anywhere near your boat or any boat that we are not in command of.
#howto #navigate #sailing #howtosail #learntosail #sailingtips
Was just wondering this and this was the first video that came up. Short and sweet simple explanation, it all makes sense now! Thanks!
Cool - glad it made sense!!!
@@SailingTipsCa Same. Googled. This video. Me: smarter. (Sort of. It takes a couple viewings and while to sink in, but we'll get there.)
@@EmpyreanLightASMR Yay it worked!!!
Ha! Vancouver to Calgary. What a spectacular drive.
Yes it is a spectacular drive - I feel very lucky to live in this part of the world!!!
Very clear explanation. Thanks for sharing.
Thanks - glad you liked it!!!
While the metric system was adopted in many countries, the gons (or gradians), also invented by French revolutionaries, were not. Right angle = 100 gons and (this is not a coincidence!) there are 10000 kilometers from the equator to the south/north pole, so 1 centigon = 0.01 gon of latitude equals 1 kilometer, much simpler than nautical miles / degrees. I'd explain nautical miles / degrees / knots by tradition and practicality (replacing all nautical maps would be a pain) rather than simplicity.
It also seems somewhat arbitrary that there are 60 minutes in a degree! There are certainly better ways to do things, but as you noted there are huge costs in making such transitions.
@@SailingTipsCa captain obvious here: base 60 somewhat makes sense in a pre-computer time. Because it gives you lots of fractions without much calculation and without remainder/modulo : 3/4 = 45, or 5/12 = 25 etc.
Gon, the main character from my wholesome and favorite anime, Hunter × Hunter. :) Ok, I'll stop. But yeah, we could have used gons (gradians) instead. Or even better, we could use tau radians. One tau radian = 2 pi radians = 360° or 400 gradians.
Also, what if the meter was defined as 1/10^9 the distance light travels in 1 French Revolutionary second? A French Revolutionary second was defined to be 1/100,000th the duration of a day (0.864 regular seconds). However, back in the late 1790s, the French decided to adopt the regular second, as the cost of converting timekeeping devices to 10 hour days, 100 minute hours and 100 second minutes would be prohibitively high. But yeah, units are fun to mess around with.
DAMN! It is so simple, I never thought about this.
Glad it made sense!
How about an analysis of current Sailing GPS Apps for Android and Apple?
Good idea! In the meantime I use Navionics, not because it’s necessarily the best, but works well enough for me, and is also used by a number of commercial chart plotter manufacturers in their off-the-shelf products.
EXCELLENT.
Glad you think so!
Perfect explanation, congru!
Wow - not just good but perfect - thanks so much!!!
Cool
Glad you liked it!
thanks
You're welcome!
I always find it odd, when people refer to a spherical object as ‘round’. I suppose it makes sense, but it always ‘feels’ wrong…
Yes you’re right “round” could be thought of as two-dimensional - maybe if you project a spherical shape onto a two dimensional UA-cam screen it’s technically correct LOL!
Thanks for educating me...been wondering about this!
Glad it was helpful!
360 degree is completely arbitrary. Kilometer is 1/40000 of earth circumference. So we can just say that there is 40degrees in a circle. And just make same calculations but much simplier and unified with on land measurments. But sailors want to feel special.
Yes it is completely arbitrary to have 360 degrees, and 60 minutes and seconds inside of those! Part of me thinks it might have been a form of “job protection” to ensure the minions couldn’t use simple math and take over the ship!
Awesomeness. Thank you.
Glad you liked it!!!
"Earth is round" Nah you lost me there
LOL…you’ll have to use statue miles or kilometres then!
@@SailingTipsCa Usually I just sail until I see the ice wall. Then turn either left or right. Its not pretty, but it gets the job done...
@@LabiaLicker That’s a pretty common approach for flat earthers, but with all this global warming you’re going to have to start looking for the mist of the waterfall instead…
2:50 of pure gold!
Glad you liked it!
Hi Gary, Did you build your F82? I’m just starting the build of an Avalon 8.2 designed by Ray Kendrick. He recommends 900 gsm 26 oz. unidirectional glass in the cross beams. Not very easy to find. Any suggestions?
Thanks
Glenn
We’ve done lots of optimizing but thankfully the original owner did most of the heavy lifting for our beams and hull (i.e. we didn’t do the original build). That said, we have ordered cloth from Composites Canada that we can’t find locally: compositescanada.com. Have you tried them?
Thanks I did try them. They didn’t have 26 oz. But they had 13 oz. They apologized for the shipping quote which was more than a full roll of glass. Great Lakes Skipper in Wisconsin has some 40 oz. Unidirectional that they will ship to Pt. Roberts for $83 usd. Never having laid up any glass that heavy I’m researching that avenue. Happy New Year.
@@glenn5ft19 26 oz. sounds crazy heavy!!! Maybe try calling a reputable boat repair facility like Keith at Blackline (www.blacklinemarine.com/) or post a query on Fix-it Anarchy on Sailing Anarchy?
The nautical miles which a pilot flies should be longer of distance than those of the sailorman. Although if the boat were as fast as the airplane, the airplane would still cover more meters than the ship does, right ?!
Excellent question! What I presented here is the historical definition, which still works well enough for rough passage planning, but as you noted airplanes flying above the surface of the earth at 35,000-39,000 ft / 10-12km / 5-6 NM above the surface of the earth would need to travel further than a boat on the surface. In addition, it turns out the earth bulges slightly at the equator which also throws things off. Therefore the modern definition of a nautical mile is 1,852 metres or about 6,067 ft.
It's true that the definition of a nautical mile as a minute of latitude is essential to navigation as we practise it, but there's nothing intrinsically sacred about it. If we used gradians instead of degrees to measure angles, where a right angle amounts to 100 grad, we could use kilometers to measure distance just as well, where 1 km = 0.01 grad in latitude.
That would, of course, be 1 centigrad, so perhaps confusion with temperature accounts for our not using that system, but I'm inclined to think it's because the DMS system was already established when the metric system came along.
You’re right - there’s nothing intrinsically sacred about a nautical mile as a minute of latitude. The point of this video was really to educate people who don’t know the rationale behind nautical miles, although there are other alternatives based on spherical geometry that might be better!
Um...measuring on the surface of the globe like that won't give you the exact distance :)
I did say "about" LOL!!!
I bet the flat earthers hate this guy. LOL
I hear they don’t sail far from land!
12 2/2 miles per hout in knoys
Hey mate, fancy doing a collab? If you made a video about foiling, SailGP or the America's Cup I could post it and we could link to your channel. Regardless, keep up the good work!
That would be cool! I have some foiling, SailGP and American’s cup videos in my library if you have a look!
@@SailingTipsCa Great! We could use 'How fast can a foiling sailboat actually go'. I wonder if having an identical video in 2 places might limit it but I could be wrong. If you were up for making a new video these are two topics I think would be popular: "How do SailGP boats fly"
"Will foiling sailboats keep getting faster?" Otherwise I can give the video you made already a try with a modified title.
a metre is defined as 1/10,000,000 from equator to pole. IT IS THE SAME
Yes that was the initial definition of the metre but it has been re-defined as the distance light travels in a certain amount of time.
@SailingTipsCa I do not believe that the metric system is anything different when measuring curved lines than any other. This argument, to my best knowledge, has zero sense.
Using knots, nautical miles, degrees, are all historical things, you could use the metric system just as well. Science uses the metric system (as most of the people of the Earth), for proper measurements.
Knots are also related to the way sailors used to measure speed, by making knots on a rope and letting it float on the water, and they measured how many knots the rope has passed for a certain time.
These are all just arbitrary measuring units. All interchangeable.
Yes all measuring systems are technically interchangeable. One of the points I was trying to make in the video is that while most people are very familiar with Euclidean geometry, which measures things in planes and straight lines, it is sometimes more convenient to use spherical geometry, especially for longer distances travelled by a plane or ship on the surface of the earth, and most people are not familiar with spherical geometry. And most people are also unaware that when using spherical geometry, one nautical mile equals one minute of longitude (which also happens to be an arbitrary measure). Euclidean geometry works perfectly well for smaller measurements (e.g. building a house) but less well for larger measurements where you’re not actually dealing with straight lines anymore.
Bullshit.
Sailors use knots because of snobism.
No that's the white pants at the yacht club!!!
It is so annoying that a lot of people seem to think this way when there is actually a good reasoning for using knots.
Fun fact, the meter was also supposed to be based on the distance between the equator and the north pole, but divided in 1/10 000 000 compared to nautical miles that is (sort of) 1/5 400.
It's also very easy to remember the formula with "a mile per minute"!!!