If you are over-weighted do you need to adjust your drysuit exhaust valve?

[Ryebrye]

Having too much weight is hassle for many reasons. One thing I'm curious about is if having too much weight means the suit is more likely to let air out the exhaust?

I found some drysuit manual that suggested that if you have too much weight you would need to close your exhaust valve down to keep air in.

At first this didn't make sense. The exhaust valve should just let air out when there's more pressure inside the suit than outside (with some factor accounting for resistance based on how far it is closed down) but then as I think about it, it seems like if you are carrying too much weight that weight needs more air in the suit to offset the weight.

So if your suit would need to have 5 psi pressure to keep enough air in for you to be buoyant, but your valve is set to exhaust anything above 3 psi, that's going to make it hard to keep enough air in and you're going to sink like a rock.

Eventually if you are way too heavy with weight, you might need so much air in the suit that it would need to be closed down entirely too keep it in, but at depth that would be dangerous because if you started to ascend without opening the valve you'll go up too fast to and need to take emergency measures to stop an uncontrolled ascent (such as fingers down the neck seal, etc)

Is that understanding correct?

 

[tbone1004]

if you are using your drysuit to compensate for buoyancy, which you shouldn't, then you will be building positive pressure inside the suit or in parts of it and that could cause the valve to bleed gas. If you are diving head up instead of flat, that will make it want to vent as well.

Air in drysuit=warmth, not buoyancy control.... It should be an essentially fixed volume throughout the dive with your BC being used for buoyancy compensation

 

[NorCalDM]

Holding air in your suit or BC just to offset weight is hard to control and not a good idea IMHO. To fix it get the weighting corrected this will also solve other issues and make your diving more enjoyable. To much air in either and you will be yoyo diving.

 

[Ryebrye]

Oh I absolutely get that this is a terrible idea, I was just wondering about how the physics of it worked

 

[PfcAJ]

It works. Crank the valve down and it holds more air. That’s all there is to it.

 

[PfcAJ]

Oh also if you have the valve closed down and you press it, it goes back to “not closed down” while you’re pressing it. Like a manual dump.

pretty handy.

 

[Celt]

I use more weight if I’m working on the bottom and use more air in the suit for heat. The auto dump is a manual dump also, we used to dump air out the cuff which is handy if you need to dump a lot of air.

 

[ontdiver]

Another issue to keep in mind is diving in more shallow depths where you may find yourself having to contend with shoals and the like. If you are not paying attention to changes in depth and expansion of gas in your suit and/or BCD, you can find yourself "popping up" too quickly. The consequences of this range from annoying/embarrassing to an untimely demise.

 

[-JD-]

if you are using your drysuit to compensate for buoyancy, which you shouldn't, then you will be building positive pressure inside the suit or in parts of it and that could cause the valve to bleed gas. If you are diving head up instead of flat, that will make it want to vent as well.

Air in drysuit=warmth, not buoyancy control.... It should be an essentially fixed volume throughout the dive with your BC being used for buoyancy compensation

The problem is that PADI (at least, maybe others) teaches using the DS for controlling buoyancy in Rec diving. The rationale seems to be reducing task-loading.

Reading a ton on here and thinking it through, I decided that sticking with my BC as primary control, consistently, regardless of exposure protection, made the most sense. Also means no fussing with the DS dump valve except maybe one click either way to tune loft maintenance.

 

[lexvil]

So for those who dislike buoyancy control with the suit, if you find at the same time that you reduce squeeze and get enough loft for warmth you find some buoyancy that is optimal, do you add weight just so you can use the b/c? Asking for a friend