Head down on deco =14% faster off gasing

**nigelh** · 14th December 2007, 11:24

Quote: (Originally Posted by Simon Mitchell)

...about to embark on a space walk

Would you care to define 'head down' in this context?

Mdemon · 14th December 2007, 12:01

Quote: (Originally Posted by nigelh)

Would you care to define 'head down' in this context?

IIRC, F=(gM1M2)/(D*D) applied to all the significant lumps in the area. Find the biggest F et voila! You know where to point your head.

Simon Mitchell · 14th December 2007, 13:29

Quote: (Originally Posted by nigelh)

Would you care to define 'head down' in this context?

Probably a fair point!

Simon M

jaap · 14th December 2007, 15:39

http://archive.rubicon-foundation.or...7/1/781973.pdf

Less gas loading with positive pressure breathing and faster gas elimination with negative pressure breathing.

Hmm...dive down with a chestmount Rebreather and do the deco with a back mounted Rebreather...

**nigelh** · 14th December 2007, 15:55

Quote: (Originally Posted by jaap)

Hmm...dive down with a chestmount Rebreather and do the deco with a back mounted Rebreather...

So my 'bad' habit of rolling onto my back on stops is actually smart?

**Freef** · 14th December 2007, 17:16

Quote: (Originally Posted by nigelh)

So my 'bad' habit of rolling onto my back on stops is actually smart?

No, it just means you are a s l u t

.

Quote: (Originally Posted by Simon Mitchell)

...loss of gravitational effect in an immersed subject, no matter what position they are in - head up, head down, sideways etc. ...

In water you have no more loss of gravitational effect than you do in the basket of a helium balloon. You are still under the influence of the Earth's pull.

Gobfish1 · 14th December 2007, 17:42

Quote: (Originally Posted by Freef)

No, it just means you are a s l u t

.

In water you have no more loss of gravitational effect than you do in the basket of a helium balloon. You are still under the influence of the Earth's pull.

well i cant do backward rools on land ,,, or in a basket ,,,

Sutty · 14th December 2007, 17:48

Quote: (Originally Posted by Freef)

In water you have no more loss of gravitational effect than you do in the basket of a helium balloon. You are still under the influence of the Earth's pull.

I think he meant gravitation effects on blood distribution (ie normal "pooling" in dependant parts eg legs), which IS affected by immersion.

**Freef** · 15th December 2007, 13:38

Quote: (Originally Posted by Sutty)

I think he meant gravitation effects on blood distribution (ie normal "pooling" in dependant parts eg legs), which IS affected by immersion.

No more than being horizontal in bed. If you were vertical in the water the blood would be in your legs to the same extent as if you were on dry land.

Being underwater does not make you 'weightless' as the training agencies would have people believe. You are just supported by the medium you are in. If you dive into a ball pool you don't sink to the bottom as you are supported by the balls. You wouldn't describe yourself as weightless.

Mark Chase · 15th December 2007, 14:48

Quote: (Originally Posted by Simon Mitchell)

Hello Mark,

I don't think you can read much into this with respect to diving. The experiment was conducted dry. The centralisation of blood volume that is achieved with the head down position in a dry subject is already achieved by peripheral vasoconstriction and loss of gravitational effect in an immersed subject, no matter what position they are in - head up, head down, sideways etc. This is not to detract from the importance of their findings for dry subjects about to escape from a submarine, about to embark on a space walk or in a couple of other contexts I can think of. However, there is probably no relevance to divers.

Warm regards,

Simon Mitchell

Thank god for that, I hate giving an inch of credit to the GUE lot

Ill go back to clipping off on the station going negative and falling asleep

Many thanks for the heads up on this as I had mistakenly believed it was relevant to diving.

ATB

Mark

14th December 2007, 11:24	#11 (permalink)
nigelh New Member Current Rebreather/s: Inspiration Vision Other CCR Other Rebreather/s: Inspiration Classic Other CCR Join Date: Mar 2005 Location: Brighton, Sussex, UK Posts: 784	Re: Head down on deco =14% faster off gasing Quote: (Originally Posted by Simon Mitchell) ...about to embark on a space walk Would you care to define 'head down' in this context? __________________ nigelh
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14th December 2007, 12:01	#12 (permalink)
Mdemon SiegeEngine II Current Rebreather/s: Inspiration Classic Home Build Other Rebreather/s: Inspiration Classic Home Build Join Date: Feb 2007 Location: SWUK Posts: 1,866	Re: Head down on deco =14% faster off gasing Quote: (Originally Posted by nigelh) Would you care to define 'head down' in this context? IIRC, F=(gM1M2)/(D*D) applied to all the significant lumps in the area. Find the biggest F et voila! You know where to point your head. __________________ www.southwestmafia.com
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14th December 2007, 13:29	#13 (permalink)
Simon Mitchell New Member Current Rebreather/s: MK 15.X Other Rebreather/s: Join Date: May 2005 Location: New Zealand Posts: 156	Re: Head down on deco =14% faster off gasing Quote: (Originally Posted by nigelh) Would you care to define 'head down' in this context? Probably a fair point! Simon M
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14th December 2007, 15:39	#14 (permalink)
jaap Normal people worry me Current Rebreather/s: Classic Kiss Other CCR RB80 / Clone Ray Other SCR Home Build Other Rebreather/s: Other CCR RB80 / Clone Ray Other SCR Home Build Join Date: Jun 2005 Location: Stockholm Sweden Posts: 437	Re: Head down on deco =14% faster off gasing http://archive.rubicon-foundation.or...7/1/781973.pdf Less gas loading with positive pressure breathing and faster gas elimination with negative pressure breathing. Hmm...dive down with a chestmount Rebreather and do the deco with a back mounted Rebreather... __________________ My initials: JAAP
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14th December 2007, 15:55	#15 (permalink)
nigelh New Member Current Rebreather/s: Inspiration Vision Other CCR Other Rebreather/s: Inspiration Classic Other CCR Join Date: Mar 2005 Location: Brighton, Sussex, UK Posts: 784	Re: Head down on deco =14% faster off gasing Quote: (Originally Posted by jaap) Hmm...dive down with a chestmount Rebreather and do the deco with a back mounted Rebreather... So my 'bad' habit of rolling onto my back on stops is actually smart? __________________ nigelh
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14th December 2007, 17:16	#16 (permalink)
Freef Custom Title Disallowed! Current Rebreather/s: Dolphin Other Rebreather/s: Dolphin Join Date: Jan 2006 Location: Land of the Freef, UK. Posts: 1,356	Re: Head down on deco =14% faster off gasing Quote: (Originally Posted by nigelh) So my 'bad' habit of rolling onto my back on stops is actually smart? No, it just means you are a s l u t . Quote: (Originally Posted by Simon Mitchell) ...loss of gravitational effect in an immersed subject, no matter what position they are in - head up, head down, sideways etc. ... In water you have no more loss of gravitational effect than you do in the basket of a helium balloon. You are still under the influence of the Earth's pull. __________________ David. Currently owner of two differently sized ankles.
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14th December 2007, 17:42	#17 (permalink)
Gobfish1 Custom Title Allowed! Current Rebreather/s: Inspiration Classic Other Rebreather/s: Inspiration Classic Inspiration Vision Evolution Join Date: Apr 2005 Location: Manchester UK Posts: 352	Re: Head down on deco =14% faster off gasing Quote: (Originally Posted by Freef) No, it just means you are a s l u t . In water you have no more loss of gravitational effect than you do in the basket of a helium balloon. You are still under the influence of the Earth's pull. well i cant do backward rools on land ,,, or in a basket ,,, __________________ Steve G Apparently not the only gay diver in the village http://drinkingliberally.org/blogs/o...nzee-glock.gif http://www.scubatunes.com/audio/vol01/mp3/HiTech.mp3
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14th December 2007, 17:48	#18 (permalink)
Sutty Classic Kiss diver Current Rebreather/s: Classic Kiss Other Rebreather/s: Join Date: Jun 2005 Location: Glossop, Derbyshire, UK Posts: 763	Re: Head down on deco =14% faster off gasing Quote: (Originally Posted by Freef) In water you have no more loss of gravitational effect than you do in the basket of a helium balloon. You are still under the influence of the Earth's pull. I think he meant gravitation effects on blood distribution (ie normal "pooling" in dependant parts eg legs), which IS affected by immersion. __________________ Never forget that life is a finite resource. Last edited by Sutty : 14th December 2007 at 17:51.
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15th December 2007, 13:38	#19 (permalink)
Freef Custom Title Disallowed! Current Rebreather/s: Dolphin Other Rebreather/s: Dolphin Join Date: Jan 2006 Location: Land of the Freef, UK. Posts: 1,356	Re: Head down on deco =14% faster off gasing Quote: (Originally Posted by Sutty) I think he meant gravitation effects on blood distribution (ie normal "pooling" in dependant parts eg legs), which IS affected by immersion. No more than being horizontal in bed. If you were vertical in the water the blood would be in your legs to the same extent as if you were on dry land. Being underwater does not make you 'weightless' as the training agencies would have people believe. You are just supported by the medium you are in. If you dive into a ball pool you don't sink to the bottom as you are supported by the balls. You wouldn't describe yourself as weightless. __________________ David. Currently owner of two differently sized ankles.
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15th December 2007, 14:48	#20 (permalink)
Mark Chase I go down for ages Current Rebreather/s: Classic Kiss Other CCR Other Rebreather/s: Inspiration Classic Other CCR Join Date: Jan 2005 Location: Kent Posts: 2,410	Re: Head down on deco =14% faster off gasing Quote: (Originally Posted by Simon Mitchell) Hello Mark, I don't think you can read much into this with respect to diving. The experiment was conducted dry. The centralisation of blood volume that is achieved with the head down position in a dry subject is already achieved by peripheral vasoconstriction and loss of gravitational effect in an immersed subject, no matter what position they are in - head up, head down, sideways etc. This is not to detract from the importance of their findings for dry subjects about to escape from a submarine, about to embark on a space walk or in a couple of other contexts I can think of. However, there is probably no relevance to divers. Warm regards, Simon Mitchell Thank god for that, I hate giving an inch of credit to the GUE lot Ill go back to clipping off on the station going negative and falling asleep Many thanks for the heads up on this as I had mistakenly believed it was relevant to diving. ATB Mark __________________ Is it supposed to make that noise ? I took my unit to the dive shop and demanded they bolt on every thing that would fit. Join my elite diving teem and get a Tshirt "Doing It Chasey"Hammerhead Eccr Advanced Diving System
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