I just took my PADI drysuit class. They say to keep the drysuit valve completely open and let all he air out of your BC then only control your buoyancy with your drysuit only by adding and letting air out. A guy I dive with says all the other agencies tell people to adjust buoyancy with the BC and only add air to the drysuit for comfort as solely using the drysuit for buoyancy can cause excessive air and result in a higher chance of a run away acent if air gets in your legs. What do you recommend for buoyancy control for a beginner with a drysuit?
Buoyancy with drysuit?
- Thread starter Seville
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BC = compensate changes in buoyancy, specifically contained and shaped air bubble, primary compensation for depth and gear changes
Drysuit = just enough gas to loft your undergarments, big bubble of places air can be
Sometimes a couple clicks tighter than all the way open keeps the drysuit from venting more often than you’d like or, in the case of the crappy low profile apeks valves, keeps them from leaking so often.
In short, PADI methodology an overwhelmingly poor choice.
Drysuit = just enough gas to loft your undergarments, big bubble of places air can be
Sometimes a couple clicks tighter than all the way open keeps the drysuit from venting more often than you’d like or, in the case of the crappy low profile apeks valves, keeps them from leaking so often.
In short, PADI methodology an overwhelmingly poor choice.
lermontov
Contributor
seeing as you already have some time using a BCD from wearing a wet suit id continue to do that and add just enough air in your dry suit to avoid squeeze -Youll need to experiment a little with weights depending on your undergarment but id recommend using your bcd as your primary buoyancy aid -further down the track youll have more experience and will know how much air is enough to make all work together. If you dry suit is a good fitting one it will make it easier -if not then extra socks willl take the volume out of your suit-feet and reduce the chance of them getting filled with air -once you have reached your dive depth then your not likely to need much more air. keep the valve half closed so that if you do vent its not going to be too dramatic a change.
Seconding the previous: PADI is wrong. Keep minimal air in the suit, just enough to avoid squeeze, compensate your buoyancy with your Buoyancy Compensator. Getting air out of the suit is tricky: even fully open the valve needs some resistance to keep water out and you need the right posture to bring the bubble over to it. The BC is much better at dumping air with its multiple wide-open valves and simple internal geometry.
With over 1,500 dives with a drysuit, you’re wrong.
First: When you use the BC for buoyancy you need to manage two bubbles. Which in an emergency can, and does, cause problems.
Second: The bubble in the suit provides warmth.
Those diving deep, greater than 35m or with twinsets, will need to use the BC for buoyancy, as the bubble in the suit will become too large to be comfortable.
Instructors who teach with the value fully open don’t understand how to use a ‘constant volume value’.
I use the suit, didn’t want to assuming PADI was wrong but it was long before I fount it to be the best system for me. You won’t have a huge bubble if you aren’t grossly over weighted. For me when I counted the squeeze I’m not needing any significant additional air for neutral buoyancy, experiment and find what works best for you, I leave the vent open unless it keeps dumping air based on activity so when needed I close it a bit.
Some do this, others do that, and a few do the other.
It is absolutely not set in stone. You do what suits you and the type of diving you do. You learn this through experience.
Personally I use the BCD/wing for course buoyancy control and the drysuit for fine control. Others use different things.
It is absolutely not set in stone. You do what suits you and the type of diving you do. You learn this through experience.
Personally I use the BCD/wing for course buoyancy control and the drysuit for fine control. Others use different things.
PADI recommends buoyancy control with single tank non compressible dry suit diving with proper weighting as a starting point for learning, and acknowledges that a non compressed neoprene drysuit or more than one cylinder will require the BC as well. The trick is proper weighting so that the drysuit bubble isn’t really big to begin with but not too small such that you’re cold.
Such strong language that someone is wrong, and yes I realize he did it to.
I personally do not dive with your methods. I use the the BC for buoyancy compensation and the drysuit for insulation, it’s not a perfect delineation though, there is a play between the two. I do this because venting small amounts of gas from drysuit is very easy but if you have to vent a lot the BC is much easier to do. Also venting from a drysuit requires a specific body position, with the BC you have multiple options depending on situation. Finally keeping air in the BC helps maintain trim, wheras using the drysuit makes it more difficult, not impossible, but more more difficult.
On descent, close 1/4 turn. If you find you are losing your bubble add a quarter turn until you reach control of the bubble. Fully open for ascents. I don't add air to my wing during the descent, generally, but i'm adding air to the suit for comfort. At depth, the air needed between comfort and neutral buoyancy goes in my wing.
I never liked the PADI method. Getting air out of your suit is more complicated and slower than dumping air from your BC, and that can be problematic for new divers. A little overinflation and you are riding the air elevator to the surface. If you are properly weighted diving a single tank, you should find that you don't need much air in your BC to control buoyancy.
That being said, I do think you should be able to control your buoyancy using only your dry suit - if your wing fails at depth, you're going to want the ability to control your ascent using your suit as a backup.
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