Reply
 
Thread Tools Search this Thread
 
Old 18 January 2012, 10:06   #1
Member
 
kerny's Avatar
 
Country: UK - England
Town: Ashton-under-Lyne Lancs
Boat name: IMOGEN
Make: Air-Craft 5.4
Length: 5m +
Engine: Suzuki df70a
MMSI: 235087492
Join Date: May 2010
Posts: 7,078
RIBase
Send a message via Skype™ to kerny
Venting dry suit fact or myth.

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.
__________________

__________________
kerny is offline   Reply With Quote
Old 18 January 2012, 10:15   #2
Member
 
chewy's Avatar
 
Country: UK - England
Town: Up Norf
Make: Avon SR4,Tremlett 23
Length: 4m +
Engine: Yam 55, Volvo 200
Join Date: Apr 2007
Posts: 5,217
More air is in the "body" of the suit than in the legs, I'll leave you to work the rest out.
__________________

__________________
chewy is offline   Reply With Quote
Old 18 January 2012, 10:37   #3
Member
 
Country: UK - Scotland
Town: Glasgow
Boat name: Thunder
Make: Halmatic Arctic 22
Length: 6m +
Engine: 2 x 150 Etec
Join Date: Oct 2008
Posts: 521
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.
__________________
GordyP is offline   Reply With Quote
Old 18 January 2012, 10:39   #4
Member
 
Country: UK - Scotland
Boat name: Wildheart
Make: Humber/Delta Seasafe
Length: 5m +
Engine: Merc 60 Clamshell
MMSI: 235068449
Join Date: Apr 2007
Posts: 4,650
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!
__________________
9D280 is offline   Reply With Quote
Old 18 January 2012, 10:40   #5
Member
 
kerny's Avatar
 
Country: UK - England
Town: Ashton-under-Lyne Lancs
Boat name: IMOGEN
Make: Air-Craft 5.4
Length: 5m +
Engine: Suzuki df70a
MMSI: 235087492
Join Date: May 2010
Posts: 7,078
RIBase
Send a message via Skype™ to kerny
Quote:
Originally Posted by chewy View Post
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.
__________________
kerny is offline   Reply With Quote
Old 18 January 2012, 11:09   #6
Member
 
Country: USA
Town: Oakland CA
Length: 3m +
Join Date: Feb 2005
Posts: 6,653
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
__________________
jyasaki is offline   Reply With Quote
Old 18 January 2012, 11:17   #7
Member
 
Country: USA
Town: Seattle
Boat name: Water Dog
Make: Polaris
Length: 4m +
Engine: Yamaha 60hp
Join Date: Apr 2007
Posts: 1,152
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.
__________________
captnjack is offline   Reply With Quote
Old 18 January 2012, 13:31   #8
Member
 
Pikey Dave's Avatar
 
Country: UK - England
Town: South Yorks
Boat name: Black Pig
Make: Ribcraft
Length: 5m +
Engine: DF140a
MMSI: 235111389
Join Date: Feb 2008
Posts: 9,865
RIBase
Quote:
Originally Posted by kerny View Post
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.
__________________
Rule#2: Never argue with an idiot. He'll drag you down to his level & then beat you with experience.
Rule#3: Tha' can't educate pork.
Rule#4:https://www.youtube.com/watch?v=unkIVvjZc9Y
Pikey Dave is offline   Reply With Quote
Old 18 January 2012, 14:11   #9
SPR
Trade member
 
SPR's Avatar
 
Country: UK - Scotland
Town: Central Belt of Scotland
Boat name: Puddleduck III
Make: Bombard
Length: 5m +
Engine: 50 HP
Join Date: Mar 2009
Posts: 2,066
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.
__________________
SPRmarine / SPRtraining
RYA Training Courses & Safety Equipment Sales
SPR is offline   Reply With Quote
Old 18 January 2012, 14:22   #10
Member
 
Country: USA
Town: Seattle
Boat name: Water Dog
Make: Polaris
Length: 4m +
Engine: Yamaha 60hp
Join Date: Apr 2007
Posts: 1,152
Quote:
Originally Posted by Pikey Dave View Post
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.
__________________
captnjack is offline   Reply With Quote
Old 18 January 2012, 14:28   #11
Member
 
mick's Avatar
 
Country: UK - England
Town: Wakefield
Boat name: Bouncer
Make: Redbay Stormforce
Length: 6m +
Engine: 2x Honda 90Hp
MMSI: 235025718
Join Date: Jun 2009
Posts: 4,023
Have you watched the guys doing the Gortex challenge they use the musto suits and jump in and float about.
__________________
mick is offline   Reply With Quote
Old 18 January 2012, 15:01   #12
Member
 
Pikey Dave's Avatar
 
Country: UK - England
Town: South Yorks
Boat name: Black Pig
Make: Ribcraft
Length: 5m +
Engine: DF140a
MMSI: 235111389
Join Date: Feb 2008
Posts: 9,865
RIBase
Quote:
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:
__________________
Rule#2: Never argue with an idiot. He'll drag you down to his level & then beat you with experience.
Rule#3: Tha' can't educate pork.
Rule#4:https://www.youtube.com/watch?v=unkIVvjZc9Y
Pikey Dave is offline   Reply With Quote
Old 18 January 2012, 15:03   #13
Member
 
Pikey Dave's Avatar
 
Country: UK - England
Town: South Yorks
Boat name: Black Pig
Make: Ribcraft
Length: 5m +
Engine: DF140a
MMSI: 235111389
Join Date: Feb 2008
Posts: 9,865
RIBase
Quote:
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
__________________
Rule#2: Never argue with an idiot. He'll drag you down to his level & then beat you with experience.
Rule#3: Tha' can't educate pork.
Rule#4:https://www.youtube.com/watch?v=unkIVvjZc9Y
Pikey Dave is offline   Reply With Quote
Old 18 January 2012, 16:02   #14
Member
 
Country: USA
Town: Seattle
Boat name: Water Dog
Make: Polaris
Length: 4m +
Engine: Yamaha 60hp
Join Date: Apr 2007
Posts: 1,152
Quote:
Originally Posted by Pikey Dave View Post
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.
__________________
captnjack is offline   Reply With Quote
Old 18 January 2012, 16:10   #15
Member
 
kerny's Avatar
 
Country: UK - England
Town: Ashton-under-Lyne Lancs
Boat name: IMOGEN
Make: Air-Craft 5.4
Length: 5m +
Engine: Suzuki df70a
MMSI: 235087492
Join Date: May 2010
Posts: 7,078
RIBase
Send a message via Skype™ to kerny
__________________
kerny is offline   Reply With Quote
Old 18 January 2012, 16:23   #16
Member
 
Pikey Dave's Avatar
 
Country: UK - England
Town: South Yorks
Boat name: Black Pig
Make: Ribcraft
Length: 5m +
Engine: DF140a
MMSI: 235111389
Join Date: Feb 2008
Posts: 9,865
RIBase
Quote:
Originally Posted by captnjack View Post
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
__________________
Rule#2: Never argue with an idiot. He'll drag you down to his level & then beat you with experience.
Rule#3: Tha' can't educate pork.
Rule#4:https://www.youtube.com/watch?v=unkIVvjZc9Y
Pikey Dave is offline   Reply With Quote
Old 18 January 2012, 16:42   #17
Member
 
kerny's Avatar
 
Country: UK - England
Town: Ashton-under-Lyne Lancs
Boat name: IMOGEN
Make: Air-Craft 5.4
Length: 5m +
Engine: Suzuki df70a
MMSI: 235087492
Join Date: May 2010
Posts: 7,078
RIBase
Send a message via Skype™ to kerny
Quote:
Originally Posted by Pikey Dave View Post
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
__________________
kerny is offline   Reply With Quote
Old 18 January 2012, 16:49   #18
Member
 
Pikey Dave's Avatar
 
Country: UK - England
Town: South Yorks
Boat name: Black Pig
Make: Ribcraft
Length: 5m +
Engine: DF140a
MMSI: 235111389
Join Date: Feb 2008
Posts: 9,865
RIBase
Quote:
Originally Posted by kerny View Post
... apparently we are catching up.
Aye, then we'll start floating face down
Quote:
Originally Posted by kerny View Post
Myself excluded of course
ain't you got a mirror in your house
__________________
Rule#2: Never argue with an idiot. He'll drag you down to his level & then beat you with experience.
Rule#3: Tha' can't educate pork.
Rule#4:https://www.youtube.com/watch?v=unkIVvjZc9Y
Pikey Dave is offline   Reply With Quote
Old 18 January 2012, 16:56   #19
Member
 
kerny's Avatar
 
Country: UK - England
Town: Ashton-under-Lyne Lancs
Boat name: IMOGEN
Make: Air-Craft 5.4
Length: 5m +
Engine: Suzuki df70a
MMSI: 235087492
Join Date: May 2010
Posts: 7,078
RIBase
Send a message via Skype™ to kerny
Quote:
Originally Posted by pikey dave View Post
aye, then we'll start floating face down
ain't you got a mirror in your house
Click image for larger version

Name:	img045.jpg
Views:	212
Size:	146.2 KB
ID:	64993

Look no adipose.

__________________
kerny is offline   Reply With Quote
Old 18 January 2012, 17:02   #20
Member
 
Pikey Dave's Avatar
 
Country: UK - England
Town: South Yorks
Boat name: Black Pig
Make: Ribcraft
Length: 5m +
Engine: DF140a
MMSI: 235111389
Join Date: Feb 2008
Posts: 9,865
RIBase
Quote:
Originally Posted by kerny View Post
Attachment 64993

Look no adipose.

Yeah, I looked like that 30 years ago as well.
Bilges here we come
__________________
Rule#2: Never argue with an idiot. He'll drag you down to his level & then beat you with experience.
Rule#3: Tha' can't educate pork.
Rule#4:https://www.youtube.com/watch?v=unkIVvjZc9Y
Pikey Dave is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




All times are GMT -5. The time now is 01:06.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.