CESA over Shared Air Ascent: Which is Best

[24940]

I came across this post today and wondered what others thought.

And seriously... in a true OOA situation, especially at reasonably shallow depths, the surface is going to be a better solution and a CESA should be executed.

Which OOA procedure is best?
[EDIT]
For the purpose of this poll, assume :

You are diving with a competent and accessible buddy
You are at max depth and that depth is 25'
You are diving as a buddy team
[/EDIT]

Please understand I am looking for which is BEST. I have done CESA from 115' and suffered no apparent ill effects, but I truly consider CESA to be the absolute worst option, next to drowning, of course.

 

[bikefox]

Depends on the dive profile. In my experience, buddy systems breakdown or may not be used on most charters. I would rather get bent than drown.

 

[24940]

Depends on the dive profile. In my experience, buddy systems breakdown or may not be used on most charters. I would rather get bent than drown.

Thanks, I edited the original post.

 

[ClayJar]

If I were to experience an OOA at the end of a protracted "safety stop", I suppose I *could* elect to make an ascent to the surface.

Considering the documented significance of ascents to DCS (I refer, for example, to the deep stop study available at DAN and as further noted on the Rubicon Research Repository), unless there was a significant breakdown in the buddy system, it is certainly better to deal with the problem at depth and to then make a proper ascent. If buddies are separated by distances such that air sharing is problematic (or even impossible), that is something that should be addressed. I do not consider that justification for teaching CESA over air sharing.

Considering the potential harmful effects, CESA should be a skill for worst-case scenarios. It should not be taken lightly, even though the overall probability of a DCS hit may be low.

(Note that I'm excluding vintage divers from this, as when you're diving steel 72s with J valves, no SPG, and all that, the procedures are significantly different than current diving practice.)

 

[diver 85]

define 'reasonably shallow depths' and give a dive profile as bikefox stated.....

 

[24940]

define 'reasonably shallow depths' and give a dive profile as bikefox stated.....

I used 25', but it could as easily be 60', which I consider to be a reasonably shallow depth.

 

[DivingPrincessE]

I voted for buddy breath because I hate CESA. It was the one and only skill that I had trouble with during OW checkout. I had to do it several times and prob could never do for real. As a result I monitor my air like crazy and stay close to my buddies.

 

[diver 85]

I used 25', but it could as easily be 60', which I consider to be a reasonably shallow depth.

BB (esp if a SS is pretty much required due to a dive profile) although either one would work IF a 'safe' profile is ongoing.....

 

[hollywood703]

I would always choose shared Air over CESA if shared Air is a REASONABLE option....Even with a competent Buddy, at a depth of 25 ft (for this example) I can make it to the surface more realistically, then taking the time to locate buddy if not Right next to him, signal OOA, and establish Shared Air...I would be at the surface already. Now at 40 ft or more, I would defintely go to buddy and use CESA as last resort.

 

[MauiScubaSteve]

Now at 40 ft or more, I would definitely go to buddy and use CESA as last resort.

I voted for buddy breath because I hate CESA. It was the one and only skill that I had trouble with during OW checkout. I had to do it several times and prob could never do for real. As a result I monitor my air like crazy and stay close to my buddies.

Please understand I am looking for which is BEST. I have done CESA from 115' and suffered no apparent ill effects, but I truly consider CESA to be the absolute worst option, next to drowning, of course.

Evidently there is some terminology/training breakdown here. In the PADI OW training, the order of priority when low on/out of air is; normal ascent (low but enough), alternate ascent (buddy accessible), controlled emergency swimming ascent (CESA), buddy breathing (buddy with no alternate), buoyant emergency ascent (last resort).

The worst case is catastrophic failure at depth with no accessible buddy where you are going to black out before reaching buddy or the surface. Hopefully you have expelled most air in lungs and as a last resort you do not vent the BC &/or drop weights to rise uncontrollably to the surface. It's much easier to revive a dead person at the surface than having to bring them up first. A chamber ride would be no bigie, if you make it that far.

Buddy breathing might happen when diving with vintage divers or if the buddy's alternate lost the mouthpiece in the excitement. The theory behind this in the fourth priority is ascending without reg in mouth while the other person takes two breaths yields more lung expansion injuries (holding breath) or reflex inhalation of water.

Controlled is the most important term in CESA, as to do it properly you exhale very gently and vent BC enough to keep ascent speed to less than 60' per minute (smallest bubbles). As long as the dive is not deeper than 100' or within 3 pressure groups of NDL limits there is no required safety stop so direct controlled ascent has minimal DCS risk.

Alternate ascent requires your buddy to be within short swimming distance, and with catastrophic failure most recreational dive buddies might not be close enough. That's why some divers carry a pony.

I have never even talked to a diver who has experienced the catastrophic failure. Icy free flows would at least allow you some breathing from free flowing reg while swimming to buddy. How fast does tank empty with cut HP or LP hose at depth? Anyway, all you people calling CESA last resort are not quite seeing the whole picture.