Dan Safety Stop

[Shocky]

The recent Safety Stop had a paregraph that recommended using the dry suit as a primary means of boyancy vs. a wing. I thought this was a Northeast wreck diver practice?

[pxh100]

I think it's common when the water is cold enough that you need the full loft of your insulation to stay warm. The manual for a Scandinavian dry suit described using the dry suit for the primary buoyancy control. Sorry I am not at my computer so can't easily find to web link to it.

[Aotus]

i'm still pretty new to diving dry. I guess it is common practice to use a drysuit for buoyancy. I'm not a real big fan of it, though maybe that just means I should practice more. All the PADI (recreational) videos I've seen recommend it, but someone told me once the rec classes from xyz agencies recommend it to OW drysuit rec divers so to minimize task loading, that way you only have one place to go to change buoyancy when ascending in particular. Aside from the interesting point Paul made about insulation, another possible benefit is that you could, in some cases, use a smaller wing or NO wing (with AL80s). thinking about it more, that probably is a good thing to be proficient at, especially if you're going to say your drysuit is your redundant buoyancy....

[divingabe]

I was thought to use my dry suit as buoyancy and my wing or bcd as backup. The trick is in the weighing and it took a few tries to adjust. Keeping warm is one reason and controlling the air bubble in the suit is another, if I remember one of the concerns was inversion and then uncontrolled ascent. In a cave situation this is not an life or death issue but in open water it is. There was a death in which this was one of the cause (T. Muffatone) on the San Diego wreck in NY. a few years back. So the thought is to have only one air bubble to adjust to remain neutral, this limits the possible confusion and error, since you need air in the suit you should therefore use it as your buoyancy control.
Gabe

[aquadog196]

Every cave diver I know only puts enough air into their drysuit to reduce squeeze. After that its the BC for buoyancy.

[Shocky]

Every cave diver I know only puts enough air into their drysuit to reduce squeeze. After that its the BC for buoyancy.

I believe that has been the standard practice for many years!

[Kelly Jessop]

Every cave diver I know only puts enough air into their drysuit to reduce squeeze. After that its the BC for buoyancy.

Exactly. I found that OW dry suit instruction teaches the student to use the drysuit as your buoyancy control, and your bcd/wing as back up. I think the real rationale is that someone ascending may not be able to vent both items to prevent an uncontrolled ascent. I think with proficiency both can be managed well.

[Jay]

My drysuit is to keep me warm. Bouyancy only as an emergency. If I can't put enough air into it to stay warm at a safety or deco stop than I did not weight myself properly.

[bamafan]

One thing to consider is the type of suit. Zach a neoprene or compressed neoprene suit needs a lot less air in them than a shell suit such as a TLS 350 etc. The neoprene suits don't require nearly as much insulation for undergarments to stay warm. I have found that I can get by in my Black Ice with a couple layers of hunting / hiking undergarments. I am good for 3-4 hours with a hood in our 69 deg water here and that is with my left arm wet from the leak in the seal in my armpit that can't be repaired. Now in 72 deg water I get hot and don't use a hood for shorter dives. Now in my TLS 350 it requires bulky undergarments which really sucks in the summer. I can't stand the floaty feet feeling I get when I add lots of air and it feels to me like my kicks are less efficient from this too.

As far as buoyancy I have tried it using my suit. It works but feel really inefficient to me due to the extra gas in my feet. I put just enough gas in the suit to keep it from being uncomfortable. I have on some long decos dumped all the air out of my wing and blow the suit up as much as possible to help stay warm. So it does have some warmth benefit.

[tbone1004]

I posted a thread on this on scubaboard and it has gotten rather contentious, but I think the situation is very different in a single AL80 where you are only ever offsetting 5lbs of air, and in a set of cave or deep wreck gear where you can be offsetting up to 25lbs of air in backgas alone. Because of that I advocate to put as much air in the suit as you want to be comfortable, but use the wing for what it is designed for which is adjusting for the weight of air in the tank since the suit buoyancy should be independent of depth.