CESA from 100 feet?

[BigTuna]

My PADI OW text says to use CESA (controlled emergency swimming ascent) at depths down to 30 feet in OOA situations (and no buddy). [You know the technique--swim up saying ahhhhh all the way.]

But a commercial diver I was talking to said he's done a CESA from 100 feet. Is that credible? What's the greatest depth you've done or know someone's done?

The answer is important because below the greatest depth (whatever it is), PADI says to drop weights and make a buoyant emergency ascent, risking DCI as the lesser of two evils. If the greatest depth is actually around 100 feet, then I don't need to take a pony along for resort diving.

OBTW, with a CESA, what's the fastest I should swim up? Slower than my smallest bubbles?

Penny for your thoughts.

 

[Blackwood]

As slowly as you can swim up without drowning.

 

[markfm]

I'm taking Mr Ed, but that's just because I wouldn't want to try a 100' shot.

 

[String]

Its definately possible. I seem to recall someone (possibly sub escape) doing it from near 300ft.

Advisable? No
Possible? Maybe

Even if you dont drown its a rapid ascent so a dive even within NDLs with an ascent of that rate could easily bend you - its NO excuse for not having a backup or redundant air source.

 

[wedivebc]

It used to be a requirement for sub qualification in Canada and probably Royal Navy. The new escape tower I think is 40ft and they use a breathing escape device but thousands have performed it

 

[String]

SETT (Submarine escape tower in the UK) is 30m (100ft) deep.

..and yes you can dive it when its not used for training too

 

[Firefyter]

I've seen it done from 100 ft. It was in warm, clear water, and he made it look easy. I wouldn't try it myself unless I had to, but it sure looked easy.

 

[String]

Submariners have the advantage of no residual nitrogen loading - the air in the sub is 1 bar. Divers dont have that luxury so rapid ascents are a whole bigger issue.

 

[Sideband]

100' started with no (very little) air in the lungs? My weights would be off in a heartbeat. The next time you are diving around 40' try exhaling then begin an ascent and see how far you get before you have to breath. If I'm not mistaken those sub escapes are started with the lungs full. You run out of air while diving when your lungs are empty. Even with air expansion I doubt you'd make it. I'm sure it's possible but not probable.

Joe

 

[DaFireMedic]

When resort diving, I make a risk vs gain assessment and I generally don't use a pony bottle. I use one for local diving when going below 60' or so because a pony bottle ascent is always preferable to a CESA. I've never done either except in practice, and have never done a practice CESA from below 25' or so. I certainly wouldn't want to try a CESA from 100', although there are people who have done it.