General question - loop volume and buoyancy

PCDiver · 2nd March 2007, 03:43

Quote: (Originally Posted by jepuskar)

My point about losing buoyancy if O2 is not being injected was to ensure I am understanding loop volume and how it relates to everything else. It wasn't meant to infer you dont have to look at your PPO2 displays.

Hi Jason, it will become very noticable during longer deco stops on pure O2 (1.5 to 1.6 PPO2). You metabolise O2, the PPO2 stays rather stable (depending on how much you are off-gassing helium and nitrogen), the volume shrinks and you start to descend slowly. Time to do a O2 flush (to get rid of the nasties in the loop and to add O2).

Okidiver · 2nd March 2007, 10:55

Quote: (Originally Posted by jepuskar)

Ok, I just had my first pool dives on a couple units last weekend and have I have been soaking the experience in...not quite obsessed yet, but getting there...it wasnt a class, but just an experience.

1) Your loop is just like your BC...the more air in it the more it has an affect on your buoyancy..meaning injecting more gas into the loop is going to increase your lift in the water column.
snipped
Jason

Jason,
I was also there last Sunday and, true to expectation, the battle with the buoyancy was a real challenge--especially at the deep end of the pool. I felt like a total rookie fool on the Inspiration, see-sawing around the deep end

. Did like the rebreather, though, never really considered it previously, but it's acquired some interest.
My second run (on the CK) was MUCH better re: buoyancy control, but I WAS doing some serious mask snorting to lower loop volume. At least I thought I was doing OK--Curt never took his eyes off me, no doubt expecting a disaster at any moment...

.
I probably made it a little more difficult on myself by clasping my hands together for both "rides" but, at least I wasn't doing the "Creature from the Black Lagoon" hand wave...

The flow on the CK was way high--gave me constant chipmunk cheeks (which didn't help buoyancy

) but, I'll chalk that one up to excessive calmness and no depth...

Great experience, hanging out with all those guys (& gal!)
Rick

**jepuskar** · 2nd March 2007, 14:29

Yes it was quite an experience..so much so I am trying to setup another one closer to home...private this time so I get more time to play..but I thought they did a good job delegating the 20 or so people there.

No matter how many times I read about the buoyancy I still sucked in as I approached the pool bottom...lolol..

2nd March 2007, 03:43	#11 (permalink)
PCDiver Submerge Productions Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Classic Join Date: Feb 2005 Location: Belgium Posts: 935	Re: General question - loop volume and buoyancy Quote: (Originally Posted by jepuskar) My point about losing buoyancy if O2 is not being injected was to ensure I am understanding loop volume and how it relates to everything else. It wasn't meant to infer you dont have to look at your PPO2 displays. Hi Jason, it will become very noticable during longer deco stops on pure O2 (1.5 to 1.6 PPO2). You metabolise O2, the PPO2 stays rather stable (depending on how much you are off-gassing helium and nitrogen), the volume shrinks and you start to descend slowly. Time to do a O2 flush (to get rid of the nasties in the loop and to add O2).
(Online)

2nd March 2007, 10:55	#12 (permalink)
Okidiver New Member Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Jun 2006 Location: Ft Walton Beach, FL, USA Posts: 86	Re: General question - loop volume and buoyancy Quote: (Originally Posted by jepuskar) Ok, I just had my first pool dives on a couple units last weekend and have I have been soaking the experience in...not quite obsessed yet, but getting there...it wasnt a class, but just an experience. 1) Your loop is just like your BC...the more air in it the more it has an affect on your buoyancy..meaning injecting more gas into the loop is going to increase your lift in the water column. snipped Jason Jason, I was also there last Sunday and, true to expectation, the battle with the buoyancy was a real challenge--especially at the deep end of the pool. I felt like a total rookie fool on the Inspiration, see-sawing around the deep end. Did like the rebreather, though, never really considered it previously, but it's acquired some interest. My second run (on the CK) was MUCH better re: buoyancy control, but I WAS doing some serious mask snorting to lower loop volume. At least I thought I was doing OK--Curt never took his eyes off me, no doubt expecting a disaster at any moment.... I probably made it a little more difficult on myself by clasping my hands together for both "rides" but, at least I wasn't doing the "Creature from the Black Lagoon" hand wave... The flow on the CK was way high--gave me constant chipmunk cheeks (which didn't help buoyancy) but, I'll chalk that one up to excessive calmness and no depth... Great experience, hanging out with all those guys (& gal!) Rick Last edited by Okidiver : 2nd March 2007 at 10:55. Reason: no coffee
(Offline)

2nd March 2007, 14:29	#13 (permalink)
jepuskar NA Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Aug 2005 Location: Chicago, IL Posts: 396	Re: General question - loop volume and buoyancy Yes it was quite an experience..so much so I am trying to setup another one closer to home...private this time so I get more time to play..but I thought they did a good job delegating the 20 or so people there. No matter how many times I read about the buoyancy I still sucked in as I approached the pool bottom...lolol..
(Offline)

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