BCD with Dry Suit?

vimaldude · Aug 31, 2009

I am considering going for a Dry suit and have a question about use of BCD with a dry suit.

According to some articles that I read about diving with Dry Suit, they all recommend to put air in the dry suit for buoyancy adjustments instead of using BCD.

My question is: if that is the case, the why is a bcd required when diving with a dry suit? Wouldn't a backplate with harness (minus wings) do just as well?

Vimal.

Kevin Carlisle · Aug 31, 2009

No one I know uses the dry suit for bouyancy.

snowflake4727 · Aug 31, 2009

I use my BC for bouyancy. Not the suit.

BonaireDan · Aug 31, 2009

The books all say to use the dry suit for buoyancy control. All the dry suit divers / instructors I know and work with, myself included, all use the BC for buoyancy control. Just enough air in the dry suit to limit the squeeze problem.

Teamcasa · Aug 31, 2009

vimaldude:
I am considering going for a Dry suit and have a question about use of BCD with a dry suit.

According to some articles that I read about diving with Dry Suit, they all recommend to put air in the dry suit for buoyancy adjustments instead of using BCD.

My question is: if that is the case, the why is a bcd required when diving with a dry suit? Wouldn't a backplate with harness (minus wings) do just as well?

Vimal.

The conventional wisdom is to use your BC (or wing) for buoyancy and your suit for warmth. Practicality speaking I use both but rely on my BC/wing for accurate buoyancy control and my suit as a redundant BC should my BC/wing fail.

There is no question that a suit could be the sole buoyancy control device but should it fail, then what? Besides, what do you really gain by leaving your wing on the surface?

fppf · Aug 31, 2009

Books and agencies will teach to only use the suit.
There logic is to reduce task loading, you only need to worry about adjusting one item on the dive.

Most divers I know use the BC for main control and just relieve the squeeze in the suit.
The logic here is that with less air in the suit your less likely to have a run away accent. The extra task loading is minimal.

The proponents of the suit only method will tell you if your weight is correct you wont have that much air in the suit to start with. However, as you start to use larger tanks you will need more lift at the start of a dive to offset the weight of the gas. With a 120 CF tank, you will swing 9 lbs between full and empty. That's a large bubble to float 9 lbs.

emoreira · Aug 31, 2009

For Buoyancy control, you must use the BCD. The only reason to put air inside the dry suit is to stay warm and to avoid being pressed at depth.
You should use a minimun amount of air inside your dry suit, just to feel comfortable and avoid folds of the suit which will mark your skin under pressure.
As any air space, it will reduce the volume with depth and increase volume as the depth reduces, so if you add some air at the botton, you have to release that air as you go up, to avoid uncontrolled bouyancy.
If you keep the air inside the Dry suit at a minimun, you do not need to think twice when going up. Finally, the dry suit vent valve has 2 positions : manual and automatic. If you leave it in automatic, as soon you go up, it will release air to avoid over-expansion. The counter point to this is that they normally leak in automatic. More often if it's a rented DS. In manula you have to release the air inside.

it_mike · Aug 31, 2009

Leaving the argument of buoyancy control aside, you should have the BC for two reasons; to float you at the surface and to deal with loss of suit buoyancy. If you were to loose the buoyancy of your suit (wet or dry), you would want to be able to perform a controlled ascent. Without your BCD, you'd be forced to ditch weights and hopefully be able to CESA.

Rainer · Aug 31, 2009

In singles, for shallow dives, with a properly balanced rig, the amount of gas needed to comfortably dive the dry suit is enough to basically maintain neutral buoyancy without touching the wing inflator. For doubles, deeper dives, etc, I use the wing for most buoyancy control (the dry suit is still obviously playing a role).

C-stone · Aug 31, 2009

It comes down to preference really. If you are not over weighted then by the time you put enough air in your suit then you will be neutral or close to it. I use only my suit for buoyancy but there is no wrong way. I think it is always best to use whatever way is most comfortable for you.

BCD with Dry Suit?

Please register or login

vimaldude

Contributor

Kevin Carlisle

Contributor

snowflake4727

Contributor

BonaireDan

Contributor

Teamcasa

Sr. Moderator

fppf

Contributor

emoreira

Contributor

it_mike

Contributor

Rainer

Contributor

C-stone

Registered

Similar threads