CESA theory

[tursiops]

That the residual gas (and you are right that I was sloppy) is not the only unknown factor in my quest. Now, you can also think that my quest is ludicrous. Take a number in the lane

I think you asked a very good question, but asked it very poorly, and responded poorly when people missed your point.
I hope to never have to do a CESA, but am comfortable with the concept and impressed by the number of people who have done it from depth and commented afterwards that it felt like they always had air in their lungs. From 30m, that 1-1.2 L left in the lungs after a "complete exhale" becomes 4-4.8 L at the surface, which is getting close to the maximum the lungs can hold (about 6 L). Note that in diving, we do not usually "completely exhale" but rather exhale normally, so we have MORE than the 1-1.2L at the worst moment. Physiology, Residual Volume - StatPearls - NCBI Bookshelf

Physiology, Lung Capacity - StatPearls - NCBI Bookshelf

www.ncbi.nlm.nih.gov

 

[Dody]

I think you asked a very good question, but asked it very poorly, and responded poorly when people missed your point.
I hope to never have to do a CESA, but am comfortable with the concept and impressed by the number of people who have done it from depth and commented afterwards that it felt like they always had air in their lungs. From 30m, that 1-1.2 L left in the lungs after a "complete exhale" becomes 4-4.8 L at the surface, which is getting close to the maximum the lungs can hold (about 6 L). Note that in diving, we do not usually "completely exhale" but rather exhale normally, so we have MORE than the 1-1.2L at the worst moment. Physiology, Residual Volume - StatPearls - NCBI Bookshelf

Physiology, Lung Capacity - StatPearls - NCBI Bookshelf

www.ncbi.nlm.nih.gov

Can I ask in French next time ?

 

[Dody]

Can I ask in French next time ?

My professional colleagues all tell me that I speak and write a very very good English. It is only on SB that I have complex.

 

[tursiops]

Can I ask in French next time ?

I hope not. I studied French and then lived in Belgium for a year, but was told that when my French was at its very best I sounded like an illiterate Belgian farmer.

 

[Blackcrusader]

That the residual gas (and you are right that I was sloppy) is not the only unknown factor in my quest. Now, you can also think that my quest is ludicrous. Take a number in the lane

I will be in aisle 4.

Well firstly a CESA is only meant to be done from a shallow depth not 20m or 30m or 40m but in life there are no givens. Many things to consider, your leg strength, your finning technique, did you get calf cramp on the way up from the sudden exertion? Can you equalize on the way up in a fast ascent? Will I black out? How much of an adrenaline rush will I have? Will I cry in panic? How would I have done a CESA when underweighted and already stuck in an overhead? Should I ditch weights first? So many unknown factors.

 

[BoltSnap]

Can I ask in French next time ?

Try Arabic next time?

 

[inquis]

You still seem to be stuck on SAC and exhale rate. They are irrelevant other than the latter being "enough" to avoid barotrauma.

 

[Dody]

Try Arabic next time?

I don’t speak the language. Just French, a bit of Dutch, Mandarin, Bahasa Indonesia and several african languages that you have never heard of .

 

[lexvil]

Here is a bottom line, is it possible; yes. Is it advisable requires a wishy washy answer, yes is there are no other options I which case it doesn’t matter, if it works and you make the surface you may or may not require medical attention, an option that is extremely limited to the dead.

it doesn’t allow for off gassing, it doesn’t allow for breathing until you find another air source, the surface is one option and another diver/ tank is another but the surface is the goal.

should you practice, not really but Bob pointed out a safe way to do so, do it with a regulator either in your mouth or in your hand, don’t inhale just exhale, this is a last ditch effort to not die nothing more or less.

 

[Dody]

You still seem to be stuck on SAC and exhale rate. They are irrelevant other than the latter being "enough" to avoid barotrauma.

I only used SAC to have an estimate of exhale rate at depth and I knew that My thinking was probably wrong. But I do think that exhale rate is important if I want to resolve the equation. If you exhale like a seal (french expression), even from 30 ft, you won’t make it.