There's a major flaw in this video. I strongly believe that every diver should carry a surface marker. You can use it as an emergency BCD. It may not have the same volume, but still. Also, a common mistake from divers when using such a device is to use their reg to inflate it. Why? why waste that precious O2 you need? Instead, use your exhalation to inflate it. It's air you're going to ditch anyways so why not "recycle" it and keep your O2 in the tank.
Because chances are if you're using your smb then you're about to ascend and should have plenty of "air" not "O2" left. There are also plenty of diving environments where an SMB isn't really necessary.
Add a D-ring to your weight belt. Clipping your DSMB line to the ring before ditching allows you to reel off the dropped belt in a controlled manner. You can also recover the belt later by just reeling it in.
You started the video stating that being overweighted would be a serious problem and could leave you stuck on the bottom, but then you didn't demonstrate this in your example. Even over weighted by 2-3 kilos you would still be able to swim to the surface, and with integrated weight pouches could even drop one pouch to assist with the ascent in a safe manner. With time, you could even remove a single weight from your belt to compensate for the pressure. You mentioned it is dangerous for misinformation to be spread, but it seems sensationalized to state serious issues, and then not show why it is, or explain that very well.
My thoughts exactly.I had more issues being underweight than overweight. A couple of times couldn't stay at 5m safety stop with BCD fully deflated and completely exhaling. I agree with his point about the weight belt, though. Dropping the whole belt is dangerous and removing individual weights is not practical in an emergency. Especially if the bottom is not near and you are dropping to a dangerous depth. Integrated weights are the way to go.
As a novice diver, I think too many training sites are not focused enough on buoyancy which is a super critical skill to know. Honestly, they just want you to get your basic certification so you can rent their equipment and go diving.
When my wife went to Cayman for her checkout dives her instructors whole class got to see how bad his buoyancy skills were. In NJ waters limited vis it wasn't so apparent.
Buoyancy is super critical?! Like up and down in an elevator or stop and go in a car. Either you learn to inflate and deflate your BC and figure out your proper weight belt (you won't sink with too little weight), then you shouldn't be scuba diving or driving a car. Is learning to breath super critical too?! LOL. Common sense, and if you don't have it - Darwin is waiting for you. What is super critical, you ask?! Not rushing to the surface fast (the bends), diving the deepest first and not last (run out of air), and stay calm in an emergency and work with your buddy to solve it rather than panic and drown both of you. Now, that is critical. Learn the basics, put your mask on and off under water, be calm, learn to buddy breath, plan your dive, and don't panic. Buoyancy should not be super critical. LOL.
As a divemaster (working or just recreational), I always take 3-5lbs more weight. Sooo many times there is someone who doesn't have enough weight and will start floating up towards the end of a dive. So, yeah, if you are with seasoned divers, go perfect weighted for yourself, going with beginners, add some to keep your random partner from fighting the float and get more bottom time.
More often than not, that situation has absolutely NOTHING to do with them “not having enough weight”, and everything to do with their constant kicking, fidgeting, flailing, deep breathing cycle, etc. All things that SHOULD have been ironed out in their very first course, their basic open water course.
As a beginner, how should I be correctly weighting? I use an app called “Buoyancy Calc” on iPhone. For me in a 3mm long with AL80 in fresh water at 175lbs it says 9.5lbs. I did experiment and took 8 for one dive and I felt like I was fighting as I got lower on air. 10 did feel heavy but I also am not good at buoyancy control and I know 10 did hold me down the whole dive and I didn’t feel like I was fanning myself down close to the end. I was taught that with ur weight at the beginning of ur dive you should float with a deep breath and then seen to about eye level with the water as you exhale
I'm new to diving but I knew almost immediately when they said in case of uncontrolled decent drop your wieght belt something didn't seem right. What good is that if you then immediately go into an uncontrollable accent? This video is exactly how to deal with the situation properly! I wish they would teach this right here
If you took a diving lesson, you'd know that the fastest one can ascend during an emergency ascent is the speed of your bubbles which is the speed of an uncontrollable ascent would be (assuming no panic kicking up). As long as you are not suppose to do decompression (advanced diving), if your tank failed, you swim up with your bubbles and exhale say at 99 feet or 3 PSI, you lungs inflate 3 times as you swim up to 1PSI at surface... then again take an entire course on scuba to learn the physics and proper training.
Well done, bro. Exactamiento. Some of us would even say that there's a worse fallacy circulated around, that the octo your friend has will been within your reach when the time comes.
Thank you Steve for making this video available for everyone. There is so much misunderstanding in a lot of divers about this topic - not their fault... it's the training agencies fault that "train" them. I hope more people take this info as serious as it has to be treated! Thanks for sharing
When I went through training (SDI) we did a similar method of weight calculation, we were also taught to completely deflate the bc periodically as you ascend to remain neutral. I have had zero problems with ascent, good advice!
wow i am confused- i thought you said that "dropping weight wont allow you to ascend if bcd fails" all you did is prove the fact you said was wrong- as if youd be stuck under water. im so lost
I dont use a Redundant Bladder but most of the time a dry suit and always two SMBs or 1 smb and a lift bag if bc has malfunction on depth. One time the iflator of a rental equipment has broken but luckily before i jumped in, so i got the chance to switch my bc. Cool video!
Cenote Angelita, south of Tulum in Mexico. One of the most amazing spots on the planet. That's not the bottom, its a thick layer of hydrogen sulfide gas.
Correct weight is important but we should never dive alone, this guy should not encourage people to dive alone and using lung as bcd... This happened to my buddy (exhaust valve failed) and I could able to fix it in 38m.. If couldn't fix it.. I could take him out using my BCD safely... Using lungs as BCD is very dangerous and what this video says is the last option and if you are alone...
Doesnt matter if your weight belt is overweighted or not, when you ditch it, your still the same weight without the belt, regardless of what was on the belt
Thank you for the great video. What is it in in this case not an option to drop some of the weights? Probably because it is a source of error. And dropping all the weights would result in an uncontrolled ascent?
Control his flotability (your weight) is absolutely the best way to dive safely (and instructions there is perfect), not only in case of failure, but also for better dive experience, better breath, better resistance to cold and current. Let me add that get your weight on a belt (an elastic kind of "marseillaise" belt) is also a best way to hold added required weight (if need), not only because you will have this weight close to your G point body, but also in case of scaphander "quit" to go in a little hole or any other reason you have to experience it. As a commercial diver, i can not pretend to practice so much this kind of best technic at work depend of the job to do (sometimes we have 40 extend Kg to stay stable on a rope to be able to weld in wave conditions in shallow water... the helmet is also heavy and more weight can be more power to work on seabed for rock destruction or any other works that require human power to be efficient, but if we can dive with "tourist" scaphander (or sometimes with rebreather to stay long time or deeper) for long range inspection (2000m long to go between 20m to 70m depth with a camera, for exemple), we always choose to be perfectly equilibrate underwater in reference to the decompression higher point with empty tanks (we are using double steel tank 10 or 12L without jaket, but aluminium if rebreather for safety tanks). When you can do it, best flotability will make your life way better and you consume of gas as low as you can too, increase your decompression point the safest way. Do not hesitate to experience things in shallow water as a game with weights before to experiment something deeper... shallow water is always more difficult technicaly for flotability management, but the best school before to go deeper, because you will have low time to no time to thinking under 50m depth (and you will thinking wrong most of the time due to narcoleptic reasons). The best school by experience to learn to control and share good experiences, best practices from other "old" divers is cave diving school (better than commercial diver for technical points, most of the time). Stay safe, don't go to search record but enjoy elements, sensations and underwater life and reliefs (or wreck). Stick the timing, check material closer, be clean with yourself and be quiet in all conditions will help you to be lucky sometime.
When I was still diving, my instructor told me about this. After talking about depths, ascend rates and weight belts, she told me that when this happens you'd better hope you remembered a small plastic bag so you can make your own float from it.
excellent technic to use outlet air to create a buoy. You first have to learn to do it perfectly to be able to do it in special time when you will NEED it. For the little story time, an old friend (dead now, in his bed...) and very old diver who used to dive to search corals (his job) was using this technic and had a perfect control of his weight at any depth. When tank was going to be close to empty, his old regulator started to be strong,... it was time for him to outlet air in his bag and hook the corals, then thinking to go up... little by little, air going to be very strong in his regulator and time to left the 120m depth along the safety line... little by little, during the way up, air was going to coming back again in the regulator, due to old regulator technology that let air come again when ambiant pressure reduce (first and second stage without compensation... the best for strong material and zero surprise experience), just enough to go to recover oxygen bottle (i can not tell you how deep it was, it is not something you can do normaly). He used to dive like that during 50 years and was one of the oldest diver to still dive (he also notice by feeling when he can go upper or not at decompression time: zero accident)... This old guy was incredible and used to go so deep to work with so less air in his back (i never see again someon euse so less air to dive) ! Just because he was very quiet and control perfectly his flotability (and because of this "recover buoy bag"). Used to dive every day (only one dive a day) !
I was down 100 feet when my some of my weights fell out of the BCD. It was on my first open water dive (in Belize) the bottom was only approximately 15 feet below but even with an empty BCD I couldn't descend to retrieve them. I was never able to get my dive buddy's attention ( banged on my tank) but he just swam away. I tried to slow my assent by kicking downward but that was futual . Luckily I had only been at depth a short time and didn't suffer any I'll effect but being as it was my first dive it did scare me because of my lack of experience.
I'm sorry that happened to you and that your buddy was such a bad partner. How were your ears and lungs? Do you think you ascended slow enough because you only lost some of your weights and not all of them?
@@Panda-ik4ukAnd probably 100ft you pretty much don't need weight to stay down. Let some air out of the BCD. I don't have my deep water cert yet so about 60ft is my max depth. At 35-60ft buoyancy is not way less of an issue due to the compressive forces
When I was working as an instructor and guide at a place(in Cyprus) where we used steel tanks I was always over weighted without any weights, because the 12L 300 bar steel tanks were so much heavier than the little weight I needed. With an AL80 I needed about 2.4 kg(3 800gr weights), but these steel tanks weighed about 18 kg in the water when full.
I had an opposite issue with my dive partner having a run away BCD. It fully inflated at 30 m underwater. Luckily we had just started our dive, and I was close enough to them to help control thier accent. But up until then everyone (including the course material) talked about BCD failures as if would only ever be loss of air in the system.
Some organisations also train for these failures. We had to train to disconnect the inflator from the BCD in these issues. But I think if you're deep, this could be hard to do on short notice. Never less, train for every failure ...
I have had two BCD incidents in the last few Dives. One was a power inflator that was leaking so my BC was filling slowly during the dive. The Simple Solution to that was to disconnect the power inflator and use it the old fashioned way. The second incident I had the power inflator hose somehow got loose where it connects to the BC itself on the shoulder. Neither incident really was much to write home about I dealt with it I signaled my partner that I had a problem and return to the boat no fuss no muss. When I got to the boat I examined the connection and tightened it up. No life-threatening situation just deal with it.
This is fine until the ally tank starts to become positive (as they do) when they are in the 70 bar left range, look on any stop tec or sport diving and peoples tanks are lifting up the jacket at the back as the tank is know positive. Do this demo @ 25m with 50 bar in the tank and it will be miles different. Yes with a lot of dives you can do it but a new diver will get in a mess...
A correctly weighted diver in a 5mm wetsuit won't even need to use their BCD down to at least 20-30m. I've been to 55m and back and not put air in my BCD.
Thank you so much for this! I’m not a diver just yet because I’m trying to get my health stabilized, so in the meantime I’m learning all that I can. This video is perfectly done for us ignorant folks. One step at a time, with clear reasoning behind everything. You are awesome! Will most definitely be coming back to this! 💚🙏
You're neutral buoyancy rocks, I took my OWD and my buoyancy sucks, need to practise a lot to control, neutral/positive/negative, I struggle with the weights, because I tend to change a lot on my wetsuit. sometimes I just use the bcd on top of my skin, others, I have just a simple jacket of 3 mm and others a full wetsuit of 5.5 mm, of course when I dive "naked" without any wetsuit most of my problems with weights disappear, but it's tough to control the belt.. and it hurts. Thank you for your clean explanation, will measure and take action on my weights.
Gives a good piece of mind as a bcd failure is realistically one of my worst fears (think yuri lipski) I’ve been properly weighting but it’s nice to see that it’s not a big issue (yuri was extremely overweighted and over equipped)
@@ee02108 if that happens remove the hose and then your BCD cannot inflate anymore and it's simple to dump the air already in it. Hose can safely and easily be removed under water and under pressure but as with all skills practice it regularly in a controlled environment:)
Nice video! Air weighs 1.29 g/l, so it is far easier to calculate the weight loss of used air than weigh your system again when at 50 bar. I use 10 bar btw. I like to be able to use my reserve.
I wish I had the time to teach this to my students. I have been working as an instructor for 7 years. One off The reason i stopped teaching is because i always found the course were rushed and when i certified students I just about managed to tik the boxes. (Also the pay isn't so great) It's not nessacerelly the instructors fault. It's a combination of the instructor/agency/dive shop and above all the whole industy. I never found an employer who wanted to pay me to teach a OW course in more then 3 days. And tbh most students wouldn't pay the money that such a course would cost. If you learned it into this depth (really learned: understand, practice and master) on your OW course and your course was 3 days or less i can assure you, you missed out on other also important skills!
as a master cert diver, privately trained by a NAVY SEAL and not from a (joke) dive shop, I was trained how to dive with and WITHOUT a BCD and lean how to control my weight and dive "neutral". So I never have to have this type of issue. I havent used a BCD in over 200 dives, spear fishing,, most at around 75- 100ft. Yes, I did have a BCD for my double 90 set up, but only needed 8 lbs of weight. cant count the times I have watched other (civy) divers have problems that could of been avoided.
I have been diving since before BCDs were around. There weren't any underwater pressure gauges either. The most important lessons that I have learned are: learn to control your breathing so that you never exhale more than half your lung capacity; never dive below 60 feet without a pony bottle.
This is great theory to know and it's something people should strive towards, however as with everything, reality is a little different. I can get to perfect buoyancy with a single for my rec dives, but with doubles..... no way. Dual HP100's full is -17lbs and that's before accounting for manifold/regs and all the other gear. I've even bought a carbon fiber backplate to reduce weight as much as possible. My doubles wing is a dual bladder for redundancy. In much the same way as in theoretically electronics (computers) also rarely if ever fail and yet I take a second Perdix AI, just in case the primary fails. Theory vs. reality.
Reality is if your BCD fails, you use one of your SMBs for lift, or you use your alternate to blow up your wetsuit, or your drysuite if you dive with one. And belive me, if you have to, you will kick that out, plenty of lift can be created with your fins + weigth drop.
Yeah for technical diving you should always have redundancies. In fact not only should you have a dual bladder wing(or wing+drysuit), you should have a liftbag and a DSMB both of which can be used for buoyancy in an emergency.
I tend to jump in, sink to the bottom, dive the wreck, if I find something interesting, then suck the pony dry then go back to the main cylinder to about 20 bar then make my way to the surface. Simples! But, in all seriousness, this is a very good educational video for doing it the *correct* way.
I was trained in emergency ascent from 25 ft. The instructor goes behind you while 25 feet underwater and shuts off your air to simulate an out of air emergency. You ascend fairly quickly, actively exhaling all the way to the surface so you dont blow out a lung. They dont do this training anymore because its considered too dangerous!
When I did my Open Water in April I was wearing 12 kilos as instructed by my instructor. It was next to impossible for me to keep off of the floor (12L aluminum cylinder)
I learned this the hard way. Back in 2003 I was 30 and decided to learned to dive. I have lived on the Gulf of Mexico all my life salty water gives me the feeling of being home. So I started going to a very popular dive school in Jacksonville FL. I passed everything did all my check out dives. For my first open water real dive we decided to go to west palm beach and do the shark bowl. After spending 30 min at 80ft it was time to go. I reached over to bump a little air back in my bcd and nothing happened. So I stood up and got the attention of my dive buddie. I was at 1000 psi and had a 5 min safety stop at 15 ft. So I dropped my led bags out of my bcd and I was still standing on the bottom looking a black tips coming in to check out my problem. I put my octopus in my wetsuit to make a redneck BCD. It only took a few short bumps to get me neutral.
If you were trained properly (OW divers aren't permitted to dive to that depth) you would have known that a couple of breaths into the oral inflation valve would have made you positive enough to make a controlled ascent whilst leaving your weighting intact and without comprimising your remaining gas or alternate air source. It's lucky you didnt suffer from DCI. Any other new divers reading this, please know never to do this. It's both stupid and reckless. We are trained correctly to know what to do in these situations and this is not it.
Warm water divers might find themselves surprised if they go diving in cold water with the necessarily thicker wetsuit. The more foam neoprene the diver wears, the more buoyancy will be lost during the descent. That can make it more difficult or impossible to swim up from depth without ditching weight.
Fair play . Great expectations from weighting ,all that time doing fin pivots , I had 8 kgs thrown at me on a dive boat once I only like 4 with jet fins . Ps people overtightening mask straps could be your next .
Thank you for all the knowledge you spread with good conscience. I have a question i hope you can answer without too harsh a judgement. If you're at 21 meters, at 80% lung volume and neutral... How will you be able to keep hovering at say 5 meters im case you wanted or needed to do a safety stop? Or even not shoot too quickly up at 3/2 meters? I cannot see how even breathing uncomfortably shallow (say 20% lung capacity) i could keep neutral buoyancy at 5/3 meters. I did not calculate my lung capacity, but just by body memory I don't feel like neutral at 21meters could translate to neutral at 5 meters just by breathing shallower. Hope the question was well understandable and can spark a positive conversation on the subject. Be well
Thank you for the comment, I am assuming that you mean with a failed BCD since this is video you posted it on. In actual practice of this as I show in the video it is possible. What I would say is that firstly you should get our full range of online training, and I am sure it will be explained to you in there, along with many other things, plus we will help you if something is not answered as you have made an invested in us www.sidemounting.com/the-shop/ secondly the key is to be correctly weighted in the first place, then having good breathing control, finning techniques and underwater skills make staying at depth with BCD failures possible.
I agree with the premise of not dropping weights to get to the surface. I'm not an instructor and here to learn, but it seems to me that dropping weights is more for gaining positive buoyancy after reaching the surface than for getting to the surface. If there is an emergency and BCD has failed, I'd get to the surface and then ditch weights to help stay there. No?
this is pretty good but i think you will run into some issues when you start carrying large quantitys of gas say a twin 12 steel with two aluminunum stages you will propabaly not be able to do that with full tanks
Thanks Samuel, we cover these test several times with all cylinder configurations. This video you will want to watch next www.sidemounting.com/lesson/technical-divers-multi-stage-drysuit-20-min/ covers tec diving wing failure with x2 steel LP 200 BAR cylinders and x2 Aluminium 80 cylinders all full. Regards, Steve
Thanks for making this video. I switched to an XDEEP ZEN and need to re-weight myself! I noticed it needs much less weight than I am used to with a regular jacket or a regular back inflated BCD.
I'm just a enthusiasts with AOWD. Thanks for your tips! You can always mention that in places with high risk / possibility of up currents like Komodo it maybe better to have a little more weight. Do you agree :)?
I don't. Currents can wrap around structures (like the pinnacles in Komodo) and go downwards. A downwards current + an overweighted diver and you're going to have a bad day. I've never seen the need to be deliberately overweighted.
Great video! I’ve got a little fine tuning to do with my weighting and I’m glad you’ve got me thinking more seriously about it. I hold very close to this, but would like to be spot on. Thanks again for this great information.
I just separate my weights so ankles & 1 kg can be removed independently of my belt. Also have a lift bag & 2x Dsmb so I can use them clipped to my belt as a buoyancy control..mine have dump valves & I make sure I can invert or detach it easily..once your on twins with 2kg torch batteries & drysuit etc etc your breathing is much less effective as a control..
With integrated weights, you could still drop one weight from your bcd. As you use up your air, the tank will be more buoyant and you will have trouble doing a safety stop and holding a steady depth if you are just a bit underweighted. I dive with 5 mil wetsuit and carry 18 lbs lead. It always works just right for me, but i will do some testing and simulate a blown bcd. That tip about using a smb for emergency buoyancy was a great idea... i would have never thought of that!
@@sidemountscubadiving Thanks for answer me , So with only 3 kilos you can dive with a 7mm wetsuit, in fresh water (test on the lake) and salt water too (test on shipwreck), this is correct? Amazing
It is a xDeep dive computer / bottom timer. But I don't think you can get them anymore, all the screens fade after a year or so of use and the built-in battery also needs replacing after a year or so as well. I would advise people to get a Shearwater dive computer now, well worth your investment. Regards, Steve
Would love to hear why double bladder is a bad idea???? Agree with being correctly weighted but also I feel like you are either diving in a 3 or maybe 5mm wetsuit. 7mm wetsuit or semidry buoyancy loss at 30m might be a bit different i think...
why do we need weight belts then? why not put the weight inside the bcd. atleast you mention the wetsuit, this is a huge part of neutral buoyancy. im sorry but i don't agree with you.. being able to emergency ascend is better than not being able to.. As an ex military diver we didn't even use a bcd.. buoyancy was found with the mm of the wetsuit and then knowing what depth you would be working at and then experience to know what weights you need.
Hi have you ever seen somebody dives with carbon fiber aluminum cilinders? I received a buoyancy table from carbondive, Austria and I'm thinking about to dive with this tuxing 6.8L China cilinder. We dive maximum 15 m. Normally 5 to 10
So if using an aluminum 80, suit up with an empty bc and a full tank, normal breathing (roughly 80% lung capacity) when properly weighted should have you floating at eye level. Then just add about 4-5lbs additional weight to allow for increased buoyancy after tank pressure drops to reserve (approx 700 psi).
You can learn this in either our backmount or sidemount online training courses - www.sidemounting.com/the-shop/ we cover what the instructors and dive agencies should be covering
Hi Steve. Thank you for this video and I like the way you demonstrate the concept of not over-weighting. However, I have a question: in your video, your lung can support at max 4.8kg of weight at the surface, which is 1.5kg more than the weight of your full tank + empty BCD (3.3kg). However, at the end of dive, suppose you have reserved amount of air in the tank (-1.3kg), and you breathe normally underwater (which means your lung presents +3.3kg positive buoyancy), in order to avoid ascending to the surface unexpectedly due to underweight, you will need to carry extra 3.3kg - 1.3kg = 2 kg of lead weights to be neutral buoyant underwater. This means you will start your dive with 3.3kg (full tank+empty BCD) + 2kg (lead weight) = 5.2kg, which exceeds the max weight your lung can support. What if you have failed BCD with full tank in this situation? You will need hard kick to avoid from sinking, won't you? Is this a contradict between the max weight you can overweight in case of BCD failure, and the min weight you need to avoid unexpected ascent at the end of dive?
Hi, I don't doubt the numbers you quote but it is important to consider the wetsuit crush too. Generally at the surface a wetsuit is very buoyant, especially when first getting in then after diving in it and crushing it, it becomes less buoyant to a degree, also the level of breathing control a diver has especially a skilled one is a lot, the ability to control different lung volumes makes a huge difference. I highly recommend if you have not already and invest £10 and watch the Masterclass series this will explain concepts like this in more detail www.sidemounting.com/product/scuba-diving-masterclass/ Regards, Steve
No it doesn't. If you knew how to dive this is basic stuff... like up and down in an elevator - add or remove air from your BC - simple - done. Way more important things to do. This is like teaching a pro football player how to walk rather than the play.
I ONLY use the BCD to stay on the surface. When i start Diving i fully deflate the BCD and never touch it under the water. You can steer everything with breathing.
There's a major flaw in this video. I strongly believe that every diver should carry a surface marker. You can use it as an emergency BCD. It may not have the same volume, but still. Also, a common mistake from divers when using such a device is to use their reg to inflate it. Why? why waste that precious O2 you need? Instead, use your exhalation to inflate it. It's air you're going to ditch anyways so why not "recycle" it and keep your O2 in the tank.
Because chances are if you're using your smb then you're about to ascend and should have plenty of "air" not "O2" left. There are also plenty of diving environments where an SMB isn't really necessary.
LOL not that you breathe O2 anyways!
Add a D-ring to your weight belt. Clipping your DSMB line to the ring before ditching allows you to reel off the dropped belt in a controlled manner. You can also recover the belt later by just reeling it in.
You started the video stating that being overweighted would be a serious problem and could leave you stuck on the bottom, but then you didn't demonstrate this in your example. Even over weighted by 2-3 kilos you would still be able to swim to the surface, and with integrated weight pouches could even drop one pouch to assist with the ascent in a safe manner. With time, you could even remove a single weight from your belt to compensate for the pressure. You mentioned it is dangerous for misinformation to be spread, but it seems sensationalized to state serious issues, and then not show why it is, or explain that very well.
My thoughts exactly.I had more issues being underweight than overweight. A couple of times couldn't stay at 5m safety stop with BCD fully deflated and completely exhaling.
I agree with his point about the weight belt, though. Dropping the whole belt is dangerous and removing individual weights is not practical in an emergency. Especially if the bottom is not near and you are dropping to a dangerous depth. Integrated weights are the way to go.
As a novice diver, I think too many training sites are not focused enough on buoyancy which is a super critical skill to know. Honestly, they just want you to get your basic certification so you can rent their equipment and go diving.
When my wife went to Cayman for her checkout dives her instructors whole class got to see how bad his buoyancy skills were. In NJ waters limited vis it wasn't so apparent.
Padi, SSI and BSAC make you nail your buoyancy control in the advanced open water programs. Cant speak for DAN but I bet its the same.
Buoyancy is super critical?! Like up and down in an elevator or stop and go in a car. Either you learn to inflate and deflate your BC and figure out your proper weight belt (you won't sink with too little weight), then you shouldn't be scuba diving or driving a car. Is learning to breath super critical too?! LOL. Common sense, and if you don't have it - Darwin is waiting for you. What is super critical, you ask?! Not rushing to the surface fast (the bends), diving the deepest first and not last (run out of air), and stay calm in an emergency and work with your buddy to solve it rather than panic and drown both of you. Now, that is critical. Learn the basics, put your mask on and off under water, be calm, learn to buddy breath, plan your dive, and don't panic. Buoyancy should not be super critical. LOL.
As a divemaster (working or just recreational), I always take 3-5lbs more weight. Sooo many times there is someone who doesn't have enough weight and will start floating up towards the end of a dive. So, yeah, if you are with seasoned divers, go perfect weighted for yourself, going with beginners, add some to keep your random partner from fighting the float and get more bottom time.
More often than not, that situation has absolutely NOTHING to do with them “not having enough weight”, and everything to do with their constant kicking, fidgeting, flailing, deep breathing cycle, etc. All things that SHOULD have been ironed out in their very first course, their basic open water course.
💯 rather more than less
Maybe keep that extra weight separate so you can ditch it and still make a controlled ascent.
As a beginner, how should I be correctly weighting? I use an app called “Buoyancy Calc” on iPhone. For me in a 3mm long with AL80 in fresh water at 175lbs it says 9.5lbs. I did experiment and took 8 for one dive and I felt like I was fighting as I got lower on air. 10 did feel heavy but I also am not good at buoyancy control and I know 10 did hold me down the whole dive and I didn’t feel like I was fanning myself down close to the end. I was taught that with ur weight at the beginning of ur dive you should float with a deep breath and then seen to about eye level with the water as you exhale
This is horrible advice and practice and it annoys me that dive shops overweight students
I'm new to diving but I knew almost immediately when they said in case of uncontrolled decent drop your wieght belt something didn't seem right. What good is that if you then immediately go into an uncontrollable accent? This video is exactly how to deal with the situation properly! I wish they would teach this right here
If you took a diving lesson, you'd know that the fastest one can ascend during an emergency ascent is the speed of your bubbles which is the speed of an uncontrollable ascent would be (assuming no panic kicking up). As long as you are not suppose to do decompression (advanced diving), if your tank failed, you swim up with your bubbles and exhale say at 99 feet or 3 PSI, you lungs inflate 3 times as you swim up to 1PSI at surface... then again take an entire course on scuba to learn the physics and proper training.
1 bar is 14.5 psi. The pressure at 0 feet is 1 bar. At 33 feet deep it is 2 bar. At 66 it is 3 bar. At 99 it is 4 bar. Your units and math are off.
I think that even you don't understand what you wanted to say
Well done, bro. Exactamiento. Some of us would even say that there's a worse fallacy circulated around, that the octo your friend has will been within your reach when the time comes.
Thank you Steve for making this video available for everyone. There is so much misunderstanding in a lot of divers about this topic - not their fault... it's the training agencies fault that "train" them.
I hope more people take this info as serious as it has to be treated! Thanks for sharing
When I went through training (SDI) we did a similar method of weight calculation, we were also taught to completely deflate the bc periodically as you ascend to remain neutral. I have had zero problems with ascent, good advice!
Thank you for the video and all your comprehensive information on BCD failure and a proper weighting.
wow i am confused- i thought you said that "dropping weight wont allow you to ascend if bcd fails" all you did is prove the fact you said was wrong- as if youd be stuck under water. im so lost
I dont use a Redundant Bladder but most of the time a dry suit and always two SMBs or 1 smb and a lift bag if bc has malfunction on depth. One time the iflator of a rental equipment has broken but luckily before i jumped in, so i got the chance to switch my bc. Cool video!
What a beautiful dive spot. The bottom is so clean and the vis is so clear. Never seen anywhere like that.
Cenote Angelita, south of Tulum in Mexico. One of the most amazing spots on the planet. That's not the bottom, its a thick layer of hydrogen sulfide gas.
Every now and again some scuba vid sticks in my mind, and that did..Thanks!
Proper weighting is absolutely imperative. Too many students are deliberately over-weighted from the get go.
Awesome explanation of propper weighting. Thank you!
Is that Angelita?
Great video btw, I will be replicating these steps at the pool. Wish I could test gear and practice like this in a cenote lol
Really good video highlighting such an important topic in scuba. A lot of agencies owe people money.
Correct weight is important but we should never dive alone, this guy should not encourage people to dive alone and using lung as bcd... This happened to my buddy (exhaust valve failed) and I could able to fix it in 38m.. If couldn't fix it.. I could take him out using my BCD safely... Using lungs as BCD is very dangerous and what this video says is the last option and if you are alone...
1. carry the plastic grocery that your morning breakfast burrito came in. 2. Breathe into said grocery bag. 3. Ascend as needed. 😂
Doesnt matter if your weight belt is overweighted or not, when you ditch it, your still the same weight without the belt, regardless of what was on the belt
Man you are realy a pro.
Greetings from Ukraine.
Thank you for the great video. What is it in in this case not an option to drop some of the weights? Probably because it is a source of error. And dropping all the weights would result in an uncontrolled ascent?
Control his flotability (your weight) is absolutely the best way to dive safely (and instructions there is perfect), not only in case of failure, but also for better dive experience, better breath, better resistance to cold and current. Let me add that get your weight on a belt (an elastic kind of "marseillaise" belt) is also a best way to hold added required weight (if need), not only because you will have this weight close to your G point body, but also in case of scaphander "quit" to go in a little hole or any other reason you have to experience it.
As a commercial diver, i can not pretend to practice so much this kind of best technic at work depend of the job to do (sometimes we have 40 extend Kg to stay stable on a rope to be able to weld in wave conditions in shallow water... the helmet is also heavy and more weight can be more power to work on seabed for rock destruction or any other works that require human power to be efficient, but if we can dive with "tourist" scaphander (or sometimes with rebreather to stay long time or deeper) for long range inspection (2000m long to go between 20m to 70m depth with a camera, for exemple), we always choose to be perfectly equilibrate underwater in reference to the decompression higher point with empty tanks (we are using double steel tank 10 or 12L without jaket, but aluminium if rebreather for safety tanks).
When you can do it, best flotability will make your life way better and you consume of gas as low as you can too, increase your decompression point the safest way.
Do not hesitate to experience things in shallow water as a game with weights before to experiment something deeper... shallow water is always more difficult technicaly for flotability management, but the best school before to go deeper, because you will have low time to no time to thinking under 50m depth (and you will thinking wrong most of the time due to narcoleptic reasons).
The best school by experience to learn to control and share good experiences, best practices from other "old" divers is cave diving school (better than commercial diver for technical points, most of the time).
Stay safe, don't go to search record but enjoy elements, sensations and underwater life and reliefs (or wreck). Stick the timing, check material closer, be clean with yourself and be quiet in all conditions will help you to be lucky sometime.
Yeah, Thank you for this video. I have not been shown how to correctly weight. I now know I've been diving with WAY too much weight. Thanks!
When I was still diving, my instructor told me about this. After talking about depths, ascend rates and weight belts, she told me that when this happens you'd better hope you remembered a small plastic bag so you can make your own float from it.
excellent technic to use outlet air to create a buoy. You first have to learn to do it perfectly to be able to do it in special time when you will NEED it.
For the little story time, an old friend (dead now, in his bed...) and very old diver who used to dive to search corals (his job) was using this technic and had a perfect control of his weight at any depth. When tank was going to be close to empty, his old regulator started to be strong,... it was time for him to outlet air in his bag and hook the corals, then thinking to go up... little by little, air going to be very strong in his regulator and time to left the 120m depth along the safety line... little by little, during the way up, air was going to coming back again in the regulator, due to old regulator technology that let air come again when ambiant pressure reduce (first and second stage without compensation... the best for strong material and zero surprise experience), just enough to go to recover oxygen bottle (i can not tell you how deep it was, it is not something you can do normaly). He used to dive like that during 50 years and was one of the oldest diver to still dive (he also notice by feeling when he can go upper or not at decompression time: zero accident)... This old guy was incredible and used to go so deep to work with so less air in his back (i never see again someon euse so less air to dive) ! Just because he was very quiet and control perfectly his flotability (and because of this "recover buoy bag"). Used to dive every day (only one dive a day) !
So glad I found your Chanel ! Thank you for being clear and straightforward
I was down 100 feet when my some of my weights fell out of the BCD.
It was on my first open water dive (in Belize) the bottom was only approximately 15 feet below but even with an empty BCD I couldn't descend to retrieve them. I was never able to get my dive buddy's attention ( banged on my tank) but he just swam away.
I tried to slow my assent by kicking downward but that was futual .
Luckily I had only been at depth a short time and didn't suffer any I'll effect but being as it was my first dive it did scare me because of my lack of experience.
I'm sorry that happened to you and that your buddy was such a bad partner. How were your ears and lungs? Do you think you ascended slow enough because you only lost some of your weights and not all of them?
Out of curiosity, why were you at 100' during your first open water dive?
@@Panda-ik4ukAnd probably 100ft you pretty much don't need weight to stay down. Let some air out of the BCD. I don't have my deep water cert yet so about 60ft is my max depth. At 35-60ft buoyancy is not way less of an issue due to the compressive forces
When I was working as an instructor and guide at a place(in Cyprus) where we used steel tanks I was always over weighted without any weights, because the 12L 300 bar steel tanks were so much heavier than the little weight I needed. With an AL80 I needed about 2.4 kg(3 800gr weights), but these steel tanks weighed about 18 kg in the water when full.
i am the dive person i try watching your videos to take a lot of ideas in underwater diving thanks
Just a beautiful video explained everything so nicely. ❤ Thks
I had an opposite issue with my dive partner having a run away BCD. It fully inflated at 30 m underwater. Luckily we had just started our dive, and I was close enough to them to help control thier accent. But up until then everyone (including the course material) talked about BCD failures as if would only ever be loss of air in the system.
Some organisations also train for these failures. We had to train to disconnect the inflator from the BCD in these issues. But I think if you're deep, this could be hard to do on short notice.
Never less, train for every failure ...
Great video. Thank you for spending the time to teach me
I have had two BCD incidents in the last few Dives. One was a power inflator that was leaking so my BC was filling slowly during the dive. The Simple Solution to that was to disconnect the power inflator and use it the old fashioned way. The second incident I had the power inflator hose somehow got loose where it connects to the BC itself on the shoulder. Neither incident really was much to write home about I dealt with it I signaled my partner that I had a problem and return to the boat no fuss no muss. When I got to the boat I examined the connection and tightened it up. No life-threatening situation just deal with it.
This is fine until the ally tank starts to become positive (as they do) when they are in the 70 bar left range, look on any stop tec or sport diving and peoples tanks are lifting up the jacket at the back as the tank is know positive. Do this demo @ 25m with 50 bar in the tank and it will be miles different.
Yes with a lot of dives you can do it but a new diver will get in a mess...
A correctly weighted diver in a 5mm wetsuit won't even need to use their BCD down to at least 20-30m. I've been to 55m and back and not put air in my BCD.
Thank you so much for this! I’m not a diver just yet because I’m trying to get my health stabilized, so in the meantime I’m learning all that I can. This video is perfectly done for us ignorant folks. One step at a time, with clear reasoning behind everything. You are awesome! Will most definitely be coming back to this! 💚🙏
You're neutral buoyancy rocks, I took my OWD and my buoyancy sucks, need to practise a lot to control, neutral/positive/negative, I struggle with the weights, because I tend to change a lot on my wetsuit. sometimes I just use the bcd on top of my skin, others, I have just a simple jacket of 3 mm and others a full wetsuit of 5.5 mm, of course when I dive "naked" without any wetsuit most of my problems with weights disappear, but it's tough to control the belt.. and it hurts. Thank you for your clean explanation, will measure and take action on my weights.
One of my favorite dives in Tulum
Gives a good piece of mind as a bcd failure is realistically one of my worst fears (think yuri lipski) I’ve been properly weighting but it’s nice to see that it’s not a big issue (yuri was extremely overweighted and over equipped)
Im more afraid of the bcd inflates and I cant stop it
@@ee02108 Good/Simple skill to practise.
@@ee02108 if that happens remove the hose and then your BCD cannot inflate anymore and it's simple to dump the air already in it. Hose can safely and easily be removed under water and under pressure but as with all skills practice it regularly in a controlled environment:)
Nice video! Air weighs 1.29 g/l, so it is far easier to calculate the weight loss of used air than weigh your system again when at 50 bar. I use 10 bar btw. I like to be able to use my reserve.
I was taught to always empty your bcd before ascending which I always do. I never had a problem ascending. Not sure what you are referring to
exactly!
You don't have to emtpty the bcd before ascending. It's wrong. You have to take out air during ascendig.
@@vincenzo9240what?
Nice well explained video.
I wish I had the time to teach this to my students. I have been working as an instructor for 7 years. One off The reason i stopped teaching is because i always found the course were rushed and when i certified students I just about managed to tik the boxes. (Also the pay isn't so great)
It's not nessacerelly the instructors fault. It's a combination of the instructor/agency/dive shop and above all the whole industy. I never found an employer who wanted to pay me to teach a OW course in more then 3 days. And tbh most students wouldn't pay the money that such a course would cost. If you learned it into this depth (really learned: understand, practice and master) on your OW course and your course was 3 days or less i can assure you, you missed out on other also important skills!
Great video though! 😉
Mine was 6 days (1 classroom, 3 pool and 2 OW) and I paid $1000 for it as a private lesson, and even that felt minimal.
as a master cert diver, privately trained by a NAVY SEAL and not from a (joke) dive shop, I was trained how to dive with and WITHOUT a BCD and lean how to control my weight and dive "neutral". So I never have to have this type of issue. I havent used a BCD in over 200 dives, spear fishing,, most at around 75- 100ft. Yes, I did have a BCD for my double 90 set up, but only needed 8 lbs of weight.
cant count the times I have watched other (civy) divers have problems that could of been avoided.
Great video should be shown to new divers.
Excellent and lifesaving information, thanks.
Hence why GUE strongly recommends you to use a drysuit where possible.
I have been diving since before BCDs were around. There weren't any underwater pressure gauges either. The most important lessons that I have learned are: learn to control your breathing so that you never exhale more than half your lung capacity; never dive below 60 feet without a pony bottle.
This is great theory to know and it's something people should strive towards, however as with everything, reality is a little different. I can get to perfect buoyancy with a single for my rec dives, but with doubles..... no way. Dual HP100's full is -17lbs and that's before accounting for manifold/regs and all the other gear. I've even bought a carbon fiber backplate to reduce weight as much as possible. My doubles wing is a dual bladder for redundancy. In much the same way as in theoretically electronics (computers) also rarely if ever fail and yet I take a second Perdix AI, just in case the primary fails. Theory vs. reality.
Reality is if your BCD fails, you use one of your SMBs for lift, or you use your alternate to blow up your wetsuit, or your drysuite if you dive with one.
And belive me, if you have to, you will kick that out, plenty of lift can be created with your fins + weigth drop.
Yeah for technical diving you should always have redundancies. In fact not only should you have a dual bladder wing(or wing+drysuit), you should have a liftbag and a DSMB both of which can be used for buoyancy in an emergency.
Thanks, really good demonstration.
ALL of this SHOULD be taught at the Open Water level during your OWSD course. "Minimum Weighting" is exactly what we teach at EVERY level.
You Dude are Awesome love you vids Hello from Newfoundland Canada
I tend to jump in, sink to the bottom, dive the wreck, if I find something interesting, then suck the pony dry then go back to the main cylinder to about 20 bar then make my way to the surface. Simples!
But, in all seriousness, this is a very good educational video for doing it the *correct* way.
I was trained in emergency ascent from 25 ft. The instructor goes behind you while 25 feet underwater and shuts off your air to simulate an out of air emergency. You ascend fairly quickly, actively exhaling all the way to the surface so you dont blow out a lung. They dont do this training anymore because its considered too dangerous!
Can you share with us what agency, course and year when you did your training?
Correct weighting is so important.
Excellent video!!! Thanks!!!
When I did my Open Water in April I was wearing 12 kilos as instructed by my instructor. It was next to impossible for me to keep off of the floor (12L aluminum cylinder)
I absolutely love this video. Ha. Thank you for this
I learned this the hard way. Back in 2003 I was 30 and decided to learned to dive. I have lived on the Gulf of Mexico all my life salty water gives me the feeling of being home.
So I started going to a very popular dive school in Jacksonville FL. I passed everything did all my check out dives. For my first open water real dive we decided to go to west palm beach and do the shark bowl. After spending 30 min at 80ft it was time to go. I reached over to bump a little air back in my bcd and nothing happened. So I stood up and got the attention of my dive buddie. I was at 1000 psi and had a 5 min safety stop at 15 ft. So I dropped my led bags out of my bcd and I was still standing on the bottom looking a black tips coming in to check out my problem. I put my octopus in my wetsuit to make a redneck BCD. It only took a few short bumps to get me neutral.
If you were trained properly (OW divers aren't permitted to dive to that depth) you would have known that a couple of breaths into the oral inflation valve would have made you positive enough to make a controlled ascent whilst leaving your weighting intact and without comprimising your remaining gas or alternate air source. It's lucky you didnt suffer from DCI. Any other new divers reading this, please know never to do this. It's both stupid and reckless. We are trained correctly to know what to do in these situations and this is not it.
Warm water divers might find themselves surprised if they go diving in cold water with the necessarily thicker wetsuit. The more foam neoprene the diver wears, the more buoyancy will be lost during the descent. That can make it more difficult or impossible to swim up from depth without ditching weight.
Fair play . Great expectations from weighting ,all that time doing fin pivots , I had 8 kgs thrown at me on a dive boat once I only like 4 with jet fins .
Ps people overtightening mask straps could be your next .
You couldn’t be more right, great video!
thanks for sharing....its a good knowledge👍👍👌👌
Thats good stuff . Back to school.;;;;;;;;
Thank you for all the knowledge you spread with good conscience. I have a question i hope you can answer without too harsh a judgement. If you're at 21 meters, at 80% lung volume and neutral... How will you be able to keep hovering at say 5 meters im case you wanted or needed to do a safety stop? Or even not shoot too quickly up at 3/2 meters? I cannot see how even breathing uncomfortably shallow (say 20% lung capacity) i could keep neutral buoyancy at 5/3 meters. I did not calculate my lung capacity, but just by body memory I don't feel like neutral at 21meters could translate to neutral at 5 meters just by breathing shallower. Hope the question was well understandable and can spark a positive conversation on the subject. Be well
Thank you for the comment, I am assuming that you mean with a failed BCD since this is video you posted it on. In actual practice of this as I show in the video it is possible. What I would say is that firstly you should get our full range of online training, and I am sure it will be explained to you in there, along with many other things, plus we will help you if something is not answered as you have made an invested in us www.sidemounting.com/the-shop/ secondly the key is to be correctly weighted in the first place, then having good breathing control, finning techniques and underwater skills make staying at depth with BCD failures possible.
I agree with the premise of not dropping weights to get to the surface. I'm not an instructor and here to learn, but it seems to me that dropping weights is more for gaining positive buoyancy after reaching the surface than for getting to the surface. If there is an emergency and BCD has failed, I'd get to the surface and then ditch weights to help stay there. No?
Perfect, well done thank you
6:44 Controlled ascent, not descent, I assumed. Thanks for your videos!
My wife appreciated this video, I can now dive safely 😜
this is pretty good but i think you will run into some issues when you start carrying large quantitys of gas say a twin 12 steel with two aluminunum stages you will propabaly not be able to do that with full tanks
Thanks Samuel, we cover these test several times with all cylinder configurations. This video you will want to watch next www.sidemounting.com/lesson/technical-divers-multi-stage-drysuit-20-min/ covers tec diving wing failure with x2 steel LP 200 BAR cylinders and x2 Aluminium 80 cylinders all full. Regards, Steve
Amazing thank you soooo much!
Thanks for making this video. I switched to an XDEEP ZEN and need to re-weight myself! I noticed it needs much less weight than I am used to with a regular jacket or a regular back inflated BCD.
What was the difference?
I'm just a enthusiasts with AOWD. Thanks for your tips! You can always mention that in places with high risk / possibility of up currents like Komodo it maybe better to have a little more weight. Do you agree :)?
I don't. Currents can wrap around structures (like the pinnacles in Komodo) and go downwards. A downwards current + an overweighted diver and you're going to have a bad day. I've never seen the need to be deliberately overweighted.
@DIVETALK would love to hear your input
Great video! I’ve got a little fine tuning to do with my weighting and I’m glad you’ve got me thinking more seriously about it. I hold very close to this, but would like to be spot on. Thanks again for this great information.
Excellent; thank you for sharing!
great video and excellent demonstration
Solid knowledge, kudos and thx for sharing 👌 keep it up
nice info, thanks
I just separate my weights so ankles & 1 kg can be removed independently of my belt.
Also have a lift bag & 2x Dsmb so I can use them clipped to my belt as a buoyancy control..mine have dump valves & I make sure I can invert or detach it easily..once your on twins with 2kg torch batteries & drysuit etc etc your breathing is much less effective as a control..
With integrated weights, you could still drop one weight from your bcd. As you use up your air, the tank will be more buoyant and you will have trouble doing a safety stop and holding a steady depth if you are just a bit underweighted. I dive with 5 mil wetsuit and carry 18 lbs lead. It always works just right for me, but i will do some testing and simulate a blown bcd. That tip about using a smb for emergency buoyancy was a great idea... i would have never thought of that!
Nice video, thanks for share . One question . the wetsuit you wear is a 7 mm, 5mm or 3 mm ?
It is a well used 7mm wetsuit (more like a 5mm) with a thermocline hooded vest underneath
@@sidemountscubadiving Thanks for answer me , So with only 3 kilos you can dive with a 7mm wetsuit, in fresh water (test on the lake) and salt water too (test on shipwreck), this is correct? Amazing
Could someone tell me what that dive computer is called? Looks clean and easy to read
It is a xDeep dive computer / bottom timer. But I don't think you can get them anymore, all the screens fade after a year or so of use and the built-in battery also needs replacing after a year or so as well. I would advise people to get a Shearwater dive computer now, well worth your investment. Regards, Steve
Would love to hear why double bladder is a bad idea????
Agree with being correctly weighted but also I feel like you are either diving in a 3 or maybe 5mm wetsuit. 7mm wetsuit or semidry buoyancy loss at 30m might be a bit different i think...
Can you demonstrate what you do when your HP hose bursts,I'd like to see it.
Yes, watch this video www.sidemounting.com/lesson/how-to-handle-lp-and-hp-failures-part-1/ enjoy
Got me thinking!!!!
why do we need weight belts then? why not put the weight inside the bcd. atleast you mention the wetsuit, this is a huge part of neutral buoyancy. im sorry but i don't agree with you.. being able to emergency ascend is better than not being able to.. As an ex military diver we didn't even use a bcd.. buoyancy was found with the mm of the wetsuit and then knowing what depth you would be working at and then experience to know what weights you need.
Hi have you ever seen somebody dives with carbon fiber aluminum cilinders? I received a buoyancy table from carbondive, Austria and I'm thinking about to dive with this tuxing 6.8L China cilinder. We dive maximum 15 m. Normally 5 to 10
So if using an aluminum 80, suit up with an empty bc and a full tank, normal breathing (roughly 80% lung capacity) when properly weighted should have you floating at eye level. Then just add about 4-5lbs additional weight to allow for increased buoyancy after tank pressure drops to reserve (approx 700 psi).
great video - well articulated and explained; very clear and easy to understand
Went through OW and never even talked about weights. How does one learn this stuff?
You can learn this in either our backmount or sidemount online training courses - www.sidemounting.com/the-shop/ we cover what the instructors and dive agencies should be covering
Where was this filmed? Looks like a spring somewhere in Florida.
This was in Angelita cenote in Mexico (close to Tulum)
Hi Steve. Thank you for this video and I like the way you demonstrate the concept of not over-weighting. However, I have a question: in your video, your lung can support at max 4.8kg of weight at the surface, which is 1.5kg more than the weight of your full tank + empty BCD (3.3kg). However, at the end of dive, suppose you have reserved amount of air in the tank (-1.3kg), and you breathe normally underwater (which means your lung presents +3.3kg positive buoyancy), in order to avoid ascending to the surface unexpectedly due to underweight, you will need to carry extra 3.3kg - 1.3kg = 2 kg of lead weights to be neutral buoyant underwater. This means you will start your dive with 3.3kg (full tank+empty BCD) + 2kg (lead weight) = 5.2kg, which exceeds the max weight your lung can support. What if you have failed BCD with full tank in this situation? You will need hard kick to avoid from sinking, won't you?
Is this a contradict between the max weight you can overweight in case of BCD failure, and the min weight you need to avoid unexpected ascent at the end of dive?
Hi, I don't doubt the numbers you quote but it is important to consider the wetsuit crush too. Generally at the surface a wetsuit is very buoyant, especially when first getting in then after diving in it and crushing it, it becomes less buoyant to a degree, also the level of breathing control a diver has especially a skilled one is a lot, the ability to control different lung volumes makes a huge difference. I highly recommend if you have not already and invest £10 and watch the Masterclass series this will explain concepts like this in more detail www.sidemounting.com/product/scuba-diving-masterclass/ Regards, Steve
Never been diving. But this video is super interesting! Thanks. This saves lives!
No it doesn't. If you knew how to dive this is basic stuff... like up and down in an elevator - add or remove air from your BC - simple - done. Way more important things to do. This is like teaching a pro football player how to walk rather than the play.
I ONLY use the BCD to stay on the surface. When i start Diving i fully deflate the BCD and never touch it under the water. You can steer everything with breathing.
Good video , thanks
what if you diving in salt water, you have bigger weight reserve you can carry ?
This is kinda silly... if your bc fails and you are over weighted, just drop weight until you gain some buoyancy
You may come up way too fast though. Depending on what depth you’re at, you might be screwed.
One question: is this fresh water or salt water?