free diving on 100% o2

[eternaljonah]

no one I know is going to try this. it was just a theoretical question i had with a dive buddy on a dive boat that had some free divers on it, they did not know either. i personally believe one would get o2 toxicity after a few meters at 40.
RickyF thanks for the article , it was interesting..

 

[cascas]

I don't know the answer either but, if you totally filled your lungs with O2 then rapidly dropped down to 40 m, that's going to give you a pO2 of 5. (Smaller volume for sure, but the pO2 will be 5) Presumably you will only be there a few seconds,and the pO2 will gradually drop as O2 is absorbed and CO2 and N2 is offgassed, but it still sounds dodgy to me!

If you breath O2 at the surface, you flush your lungs of N2... There will be no N2 to offgas. N2 is not used by your body when breathing air, and you body cannot produce N2 while you are alive.. ( i am not sure if a body will produce N2 when dead though )

 

[lowviz]

Nice find! But IIRC, static apnea record attempts are performed floating face down on the surface with the absence of all motion. Anything about diving to depth?

 

[nimoh]

Nice find! But IIRC, static apnea record attempts are performed floating face down on the surface with the absence of all motion. Anything about diving to depth?

I'm guessing they didn't include it in the study because of the dangers of oxygen toxicity...but there I go again with some crazy, unsubstantiated theory

 

[dumpsterDiver]

If you breath O2 at the surface, you flush your lungs of N2... There will be no N2 to offgas. N2 is not used by your body when breathing air, and you body cannot produce N2 while you are alive.. ( i am not sure if a body will produce N2 when dead though )

No nitrogen to offgas? The body will be SATURATED with nitrogen at the surface, at depth, the body and blood will still be carrying a lot of nitrogen and I see no reason why it would not diffuse into the lungs which would presumably be filled with oxygen (under this scenario). The nitrogen would diffuse from a high PP to a lower PP area, right?

 

[beaverdivers]

Interesting questions!

 

[Duke Dive Medicine]

Nitrogen is off-gassed with breathing 100% O2 on the surface. U2 pilots do this pre-flight to reduce the risk of altitude DCS. It's also been looked at in submarine escape scenarios. The amount of N2 remaining in the body will depend on how long the diver breathes 100% O2 on the surface.

This isn't an endorsement of the practice, but the extremely deep tests on O2 that were done in the 30's suggest that a diver with a lungful of O2 on a breath-hold would not be at pressure for long enough to suffer CNS O2 toxicity symptoms. Reference: Donald, K Oxygen and the Diver, SPA limited, 1992.

 

[GROBIOG]

Breath EANX 32% instead

 

[lowviz]

...//...This isn't an endorsement of the practice, but the extremely deep tests on O2 that were done in the 30's suggest that a diver with a lungful of O2 on a breath-hold would not be at pressure for long enough to suffer CNS O2 toxicity symptoms. Reference: Donald, K Oxygen and the Diver, SPA limited, 1992.

DDM, thanks for the info and reference.

WOW, pricey book! http://www.amazon.com/Oxygen-Diver-Kenneth-Donald/dp/1854211765

 

[GROBIOG]

DDM, thanks for the info and reference.

WOW, pricey book! http://www.amazon.com/Oxygen-Diver-Kenneth-Donald/dp/1854211765

You could save considerably by buying it used

1 new from $265.00 10 used from $264.99