Back to: Free Training | 7 h 13 min split over 50 videos
00:15 Overview Of Our BCD Failure Exercise
00:50 What The General Dive Industry Want You To Believe
01:13 This Is What Correct Weighting Is
02:06 Lung Capacity Testing
03:25 Test To Prove I am Correctly Weighted
04:26 We Simulate A BCD Failure At 25 metres
07:00 Extract From End Of Dive Weight Check Video
07:33 Common Problems That Many Scuba Divers Have
16 Comments on “BCD Failure : Single Cylinder”
Thanks for this it is really informative as various people have said I am over weighted but they have never offered instruction on how to remedy this issue, if i was to show them this video they would simply say I know that and then teach based on what they have learned by watching this, I have been frustrated with some of my instructors as they have not been able to offer the kind of detail offer on this site, they may simpley not know the difference as people can be stuck in their ways and pride as they say comes before a fall or a student drowning, but lets hope not.
Thanks for comment Neville, one of the big reasons I made videos like this and this one in particular free of charge was for the greater good “so to speak” it will help all the divers and instructors you are talking about, to dive better and be more aware for the next students they meet!
All I can say Steve is wow! I have struggled with proper weighting even after taking a peak buoyancy course. I have never seen another instructor explain weighting like this. Thank you for the great info.
Thanks Brad, and what’s funny is this video is not even the one where I actually explain correct weighting buoyancy, those videos are included in the sidemount or backmount full paid online training I have 😉
I realized if I was perfectly neutral at the start of a dive than I’d be too light at the end of the dive. My thought was that an AL80 tank holds 77.4 cubic feet and air weighs 0.0807 pounds per cubic foot (depending on temperature). So a full tank has approximately 6.25 pounds of air. You typically leave a pound of air, or more, in the tank. So you probably need to add 5 to 6 pounds of weight at the beginning of the dive to compensate for the air you breath.
For a 100 cubic foot tank the weight swing would be 100 * 0.0807 or 8.07 pounds. So beginning of the dive find perfectly neutral and add 7 or 8 pounds.
Does this sound correct? This is essentially how I figured out how much lighter my kit would be once the tank was close to empty.
Hi Darrell, thanks for you comment. Of course the numbers do matter but I show people not to focus on them and instead teach an in-water and end of dive underwater “correct weight checking method” it leaves no room for error and your “changing” body mass, exposure suit and everything you are diving with is taken into account. That is available in my backmount or sidemount complete online series. Regards, Steve
Thanks Steve awesome video! I am a new student of Steve Davis here in NZ and struggled to get my weighting correct recently on a Sidemount Fundamentals course using my new drysuit (Whites, with 4th Element Arctic under garments (thick ones!). I had up to 8.5 Kgs of lead in the back of my XDeep onboard and was really bouyant at the end of the dive at 50 Bar in both cylinders. I could not believe how bouyant I was using 2 steel 12litres tanks as I used to to dive in a 2 piece old wetsuit 7mm and only needed a max of 5kgs with a twin set backmount. This video is the first time I have seen an analysis of each item we use and its impact on the whole!! Gives me great food for thought and ideas. If there are 2kgs of air in each tank, does this mean I will need to carry another 4kg of lead using the drysuit? Regards, John Read
Hi John, Glad your enjoying my online training and Steve Davis knows his stuff and also has access to my complete online materials. I see you only have access to my free online training course, which is why you don’t know the answer to your question. You need to watch and follow closely all my weight checking videos (surface and end of dive checks) then 100% you will be able to get your weighting right in your wetsuit and drysuit. Don’t hesitate invest in one of the packages, if you talk to Steve Davis he can give you his referral code and you can get 5% off when using that 😉 Regards, Steve
Awesome Steve, thanks very much!
Regards
John
PS: just got my new XDeep Stealth Tec BCD and really looking forward to trying it out!!
Absolutely brilliant videos, I’m going to enroll soon as I get paid this month, wish I had seen these videos earlier, I feel much more confident in my diving, just after watching your free videos, and then enroll on a sidemount course with instructor, to get a good grounding.
Great video! And awesome that you include it in the free part of your training for all to learn why being correctly weighted is so important… a skill that many divers often learn very late in their diving journey.
Thanks Steve – you rock!
hi Steve this material really open me on proper weight checking,
What you do when you have not exacly lead box what you need ?(kg), after calculate to be perfect bouyant in water,
for example you need lead 1,3 kg ,so do you make it – DIY 🙂
Yes I know melting lead is harmful, but is very easy to make lead box what exacly KG need.
still continues your online course,
And I must say no one from many instructors tell me about weight checking as you in one movie
Thanks for reply
Thank you for feedback Rafal, I suggest rather than messing round melting lead to make custom weights, just buy lead shot and then you can get exact weight for your home setup (just need suitable soft weight pouches to put it in). Weighting checking is one of the most important skills that is for sure. Cheers, Steve
Great video. Like most instructors I spend a lot of my time trying to correct divers that are
a) underweighted because they dont understand their air weighs 2kg – and cant stay on their safety stop OR
b) overweighted because that ensures they can ‘get down’ (thats what their last instructor told them).
I really like the visual of weighing the set in the water full and empty.
One question. You point out that the gas consumption will make set up to 2kg lighter at the end of the dive. Then you show your lung vlume allowing you to take 3.3kg + 1.5kg = 4.8kg for the dive. But surely you need 2kg or you could be 0.5kg to bouyant at the end – when you might be trying to do stops?
What am I missing here?
Hi Al, we explain this in full with the end of dive weight check videos found in the sidemount, all divers and backmount online training courses. If I was 0.5kg too bouyant personally I have the breathing control to handle this amount quite easily, with the lead weights I show to sink wetsuit etc in the video that is good and brings education to it but the real test is empty BCD, 5 metres, 50 BAR in cylinder(s) and hold 50% lung volume hold and stay neutral, a diver can breathe up and down from there but that is the point we agree for a correctly weighted diver. Regards, Steve
I like the « What If » scenario concept. Great experience sharing tool for the community.
AC