What is the deepest you can do an OOA?

[H2Andy]

This thread may be an interesting mental exercise ... but a far more practical question would be "What should I be doing to make sure I never have to make a CESA?"

those are my thoughts exactly

plan and execute your dives so a CESA is never necessary

 

[Blackwood]

As you assend your lungs go from feeling empty to not feeling so.

Sure, but feeling empty or full won't change your physiological urge to vent CO2.


I can refrain from breathing just as long with full lungs as I can with empty.

 

[Blackwood]

This thread may be an interesting mental exercise ... but a far more practical question would be "What should I be doing to make sure I never have to make a CESA?"

So change the question to: "If you are at 100FSW and you and your buddy simultaneously blow all your burst discs, can you make it up" (or something like that).

Just ignore the likelihood (or lack thereof) of it happening

 

[cerich]

Sure, but feeling empty or full won't change your physiological urge to vent CO2.


I can refrain from breathing just as long with full lungs as I can with empty.

you need to breath out the whole time, having a "full" feeling makes you not have to fight the urge to breath in.

Holding your breath on a CESA will most likely kill you.

 

[H2Andy]

having a "full" feeling makes you not have to fight the urge to breath in.

i don't think this is correct

the urge to breathe in depends on the amount of CO2 in your system, not how full your lungs are or not

 

[*Floater*]

I can easily hold my breath for about 1 min, maybe 2 if my life depended on it, and even if I blacked out, maybe I could still get a minute or two in of unconscious ascent with an inflated BC (but then I might drown on the surface). So swimming as fast as 60' per minute (faster if necessary) I could easily do an OOA ascent from 100'. However, I might end up bent on the surface.

The other question is about how much gas I had in my lungs to start with. The 1-2 min breath-hold is at home when I'm sitting here relaxed and just took a full breath. OTOH, the gas in my lungs would be expanding as I ascended so maybe I could use that to my advantage to make it last a little longer. Also, if there was gas in my BC then I could take a hit of that from the power inflator/deflator. My strategy (assuming I could remain calm and collected) would be to start off at a fairly fast pace, but then stop for a mini-safety stop IF I had enough gas in my lungs or BC around 20' or 10' or at least slow down closer to the surface and of course I'd breathe out to avoid over-expansion injuries.

 

[MXGratefulDiver]

i don't think this is correct

the urge to breathe in depends on the amount of CO2 in your system, not how full your lungs are or not

If you are breathing out, you are removing CO2 from your system. As long as you are breathing out, the CO2 level continues to reduce ...

... Bob (Grateful Diver)

 

[HowardE]

http://www.scubaboard.com/showthread.php?t=114092

Here's the old thread I was talking about.

 

[gangrel441]

Although being bent is better than dead it can sometimes be the same thing. Various decompression injuries involving bubbles in the blood stream due to rapid formation can kill (not just holding breath). "Bent" can also mean "paralysed" or at least leave some kind of permanent physical damage. Its a lottery. Best to avoid putting yourself in a situation where theres an increased risk of it over an alternative solution.

None of this factors in to the decision in the stated scenereo, as getting bent MAY kill you LATER, but drowning WILL kill you NOW. You do what you need to survive, and in this case, that means heading for the surface, keeping your reg in your mouth, trying to keep your ascent rate under 60 fpm, venting your lungs all the way to the surface. I take precautions to avoid ever having to use this procedure, but sometimes precautions backfire.

I am assuming you use a pony. So what happens if you are at 110, fail to track your air consumption, go OOA, switch to your pony, and before you start your ascent, your LP hose on your pony reg blows? Do you have a third redundant source? A fourth? A fifth? Unlikely scenereos are killers.

 

[cerich]

Therein lies the issue ... they train for it. (2 whole days in escape training before they are doing it) Furthermore, unless I'm misreading, the HMS Dolphin would be a naval vessel ... which means the people who train for 30 meter CESA's are young, in excellent physical shape, and receive skills training far in excess of what your typical recreational diver will ever get.

Nope they are Submariners of every age from 19 or so thru to 50 or so. Many of them are in no better shape than the average recreational divers, subs don't really promote exercise....

If that's the case, it's not a good comparison. The difference in mental approach alone would be a huge factor determining the success or failure of the exercise.

Most of these guys aren't divers and poor swimmers, if they can get it any diver can

Furthermore, as with all training, when you first try something you are generally going to suck at it. You make mistakes. You get stressed. You generally fail at it the first attempt ... and perhaps the first few attempts. In the real world, doing a CESA isn't something you want to fail at.

AGREE!!!

Recreational divers don't train for doing a CESA ... nor, IMO, should they. The risk of hurting yourself outweighs the potential benefit. A better effort is to plan and train for ways to avoid ever putting yourself in the situation where it is necessary.

We do teach CESA in CW but in a way to min. liablity, IMHO we are short changing our students. There is no possible way to ever train so you NEVER have no other ption, real life isn't that easy to plan or train for...

This thread may be an interesting mental exercise ... but a far more practical question would be "What should I be doing to make sure I never have to make a CESA?"

... Bob (Grateful Diver)

my comments in red