Drysuits and descents

[TSandM]

Descents continue to be my bete noir. As a result of some very good tips, I no longer do them on my back but I am still having some trouble initiating them. I do not think it is a weighting issue, because at the end of the dive, I can maintain depth anywhere I want (swam in at 8 feet of depth today). I don't think it is a breath control issue any more, and I am NOT kicking as I go down, but I still don't want to sink.

What I think is going on is air trapping in my drysuit, and later in the dive, the pressure at depth has helped get rid of it and therefore I have no buoyancy issues late in the dive.

I am attempting to begin the descent in a vertical position, with my arm raised to allow venting. I have even pushed the purge button on the drysuit valve, without discernible effect. I DO have a lot of buoyant layers under the drysuit, as I am plagued by cold and battle it with polarfleece, and I wonder if that's the problem.

Any insights?

 

[Rick Inman]

Those little pockets of air here and there will get 'ya... In the BC, in the DS, in the lungs.

Exhale all the way... did I say ALL the way? Squeeze, push, hug, vent and exhale some more.

After a bunch of dives doing this while your buddies just seem to effortlessly drop, it will happen for you too.

Relax. It's all good!

EDIT: And, oh yeah, are you diving a BC with a foam back pad? If so, throw that air trap pad away!

 

[Snowbear]

One thing that helps me, actually mostly in winter when I add an extra layer of fleece, is pre-venting before I get in the water...... the ol' push the purge valve, squat down and push the gas out so you're shrink wrapped when you stand back up. Then when in the water, take a second to make sure you're vertical and the exhaust valve is the highest point and vent again. That way the only gas I have to worry about venting for the descent is that which is in my lungs and wing. By pre-venting my drysuit and fully exhaling (and holding that), I often don't even have to fully vent the wing before I start sinking.

One thing I notice new divers doing.... as soon as they start sinking, they take a breath.... wait a couple seconds until your head is at least a couple feet under, then take a breath as you get horizontal.....

 

[Diver0001]

I am attempting to begin the descent in a vertical position, with my arm raised to allow venting.

There's maybe part of your problem.

Where is the vent on your drysuit? On your finger tips? The vent has to be the highest point. Raising your arm will trap air in the arm. Maybe two litres or more. You need to be aware of the vent, not the arm.

Crouching and holding the neck seal open to get some of the air out during donning might help too but I suspect you've already started doing that.

R..

 

[CIBDiving]

You've gotten some good advice so far, I'l try not ot muck it up.
I'm going to guess that your exhast valve is upperarm mounted.
As Diver0001 said 'don't raise the arm over your head'. But you can raise it so the valve is the highest point. Have the forearm pointed slightly downward, and now the fun part, 'pump' your arm like you were trying to make those rude noises with your armpit but don't put the other hand under the arm, try to keep the valve as the highest point. This will pump out the remaining air.

 

[CIBDiving]

One thing that helps me, actually mostly in winter when I add an extra layer of fleece, is pre-venting before I get in the water.....

SHEEESH!! up here in the winter I try to prevent getting Out of the water

 

[jiveturkey]

Do you have the same problem on your second dive of the day? Sometimes it's a matter of just relaxing. I'm always more relaxed on the second dive and which makes it easier to get all the air out of your lungs.

 

[jiveturkey]

There's maybe part of your problem.

Where is the vent on your drysuit? On your finger tips? The vent has to be the highest point. Raising your arm will trap air in the arm. Maybe two litres or more. You need to be aware of the vent, not the arm.



..

Don't just mimic the chicken wing, be the chicken wing.

 

[Snowbear]

SHEEESH!! up here in the winter I try to prevent getting Out of the water

Cool! I'm always looking for buddies.... wanna dive

 

[CIBDiving]

Cool! I'm always looking for buddies.... wanna dive

You bet! what you got going this week end. I got 2 big bottles of nitrox just straining to get out. I'm supposed to rerun some of the guide lines at smitties cove one of these days but......