Venting dry suit fact or myth.

[kerny]

If you don't vent your dry suit and you go overboard can you drown legs up, is this a fact or a myth ? I'm sure there was a video of this on youtube a few years back but I can't find it. As it happens!! I always vent mine after putting it on.

[chewy]

More air is in the "body" of the suit than in the legs, I'll leave you to work the rest out.

[GordyP]

If you fall in head first the all the air will end up in your legs, if this happens you can curl into a ball and roll forward to try to get you head up again.

[9D280]

I did and a lifejacket (or possibly more likely in a dinghy - bouyany aid) kind of doesn't give it much room to stay there as it compresses the suit round your torso.

And when you enter the water, the air will naturally be pushed to the top....or your feet if you go in head first.......


Now, if you have a nice auto inflating lifejacket that may redress the balance, but I'd be venting mine - if nothing ese you don't spend the day doing Michelin man impressions!

[kerny]

Originally Posted by chewy

More air is in the "body" of the suit than in the legs, I'll leave you to work the rest out.

I would have thought that there would be more or if not the same amount of trapped air in the legs as in the body. My suit has elasticated waist and latex socks so including both legs from waist down it can hold quite a lot of air.

[jyasaki]

Doesn't matter where it is. Air in the suit is free to move to the less pressurized area, i.e. the last thing to dip underwater. Water pressure will shrink-wrap the submerged part of the suit to your body, and the bubble ends up at the surface. As has been said, if you are feet-up, curl up in a ball, right yourself by swinging your arms, the extend your legs. The bubble will move to the torso and neck of the suit and your equilibeium will be restored.

jky

[captnjack]

You won't naturally hang head down. The natural position even without any kind of life jacket will be flat, either face down or face up. Just because some gas was pushed out of your torso does not make your chest negative/sink. There's still a good amount of positive bouyancy up there with your lungs and residual gas in the suit. It may take some time to shift flat way naturally or you can just help it along by doing a "situp" which is the the same as this ball curling motion. Its not at all difficult or unnatural.

[Pikey Dave]

Originally Posted by kerny

If you don't vent your dry suit and you go overboard can you drown legs up, is this a fact or a myth ? I'm sure there was a video of this on youtube a few years back but I can't find it. As it happens!! I always vent mine after putting it on.

Nope not a myth. I was once dragged up from 45m to 20m by a diver who had lost his weight belt & inverted. I let him go at 20m or we would have both finished up in the chamber. He spent 3 days in hospital.

[SPR]

I got an Auto dump value fitted to my suit , just pug your dry suit on and go for a walk in water you will see your the effect at top...UHF suit gets clingy on the bottom half and puffy at top!

S.

[captnjack]

Originally Posted by Pikey Dave

Nope not a myth. I was once dragged up from 45m to 20m by a diver who had lost his weight belt & inverted. I let him go at 20m or we would have both finished up in the chamber. He spent 3 days in hospital.

How is this related to falling overboard with 1ata gas in your suit? Many RIB and rafting oriented drysuits don't even have inflation/deflation valves.

[mick]

Have you watched the guys doing the Gortex challenge they use the musto suits and jump in and float about.

[Pikey Dave]

Originally Posted by captnjack

How is this related to falling overboard with 1ata gas in your suit? Many RIB and rafting oriented drysuits don't even have inflation/deflation valves.

Errrm! Because air at whatever pressure, will float in water. If you have air in your suit & invert, it will rise to the highest point, in my case & Kerny's hypothetical situation , the feet end. result= feet up, head down :nono:

[Pikey Dave]

Originally Posted by SPR

I got an Auto dump value fitted to my suit , just pug your dry suit on and go for a walk in water you will see your the effect at top...UHF suit gets clingy on the bottom half and puffy at top!

S.

You might want to chell speck that

[captnjack]

Originally Posted by Pikey Dave

Errrm! Because air at whatever pressure, will float in water. If you have air in your suit & invert, it will rise to the highest point, in my case & Kerny's hypothetical situation , the feet end. result= feet up, head down :nono:

Right.
Are you actually a diver? Have you tried floating head down feet up at the surface? Just a suit on no weighbelt or tank etc. You can't do it. There is residual air in the chest portions of the suit, there's some gas in your lungs too, there's adipose tissue. Your head is not a massively negative weight with these purportedly bouyant feet sticking up in the air like a buoy.

Really just dive in sometime. You won't float feet up. Within a few seconds you will be horizontal. Face down maybe but roughly horizontal. Then just roll over.

I would still recommend life jackets despite the inherent bouyancy of a drysuit.

[kerny]

[Pikey Dave]

Originally Posted by captnjack

Right.
Are you actually a diver?.

Yup, since 1976, couple of thousand dives in that time, stopped counting years ago. Been diving trimix rebreathers since 2003, have done dozens of +100m dives
A Neoprene dry suit will indeed float you horizontally as it is inherently bouyant, a membrane surface suit similar to the OP's has no intrinsic bouyancy & relies on the trapped air inside, this will migrate to the highest point. If you upend in a membrane suit (ie do a surface dive) you WILL hang head down. We used to teach this in the pool & how to recover from it, i.e. as previously mentioned, curl into a ball, roll & force the air into the chest area.
Re the adipose fat, maybe we don't carry as much on this side of the pond as our cousins

[kerny]

Originally Posted by Pikey Dave

Re the adipose fat, maybe we don't carry as much on this side of the pond as our cousins

Erm ...according to recent statistics... apparently we are catching up. Myself excluded of course

[Pikey Dave]

Originally Posted by kerny

... apparently we are catching up.

Aye, then we'll start floating face down

Originally Posted by kerny

Myself excluded of course

ain't you got a mirror in your house

[kerny]

Originally Posted by pikey dave

aye, then we'll start floating face down
ain't you got a mirror in your house

Look no adipose.

[Pikey Dave]

Originally Posted by kerny

Attachment 64993

Look no adipose.

Yeah, I looked like that 30 years ago as well.
Bilges here we come