Frequency of advanced divers practicing CESAs ? [Poll]

[TMHeimer]

I feel the need to respond.

I once held the very same view. My PSD instructor put that soundly to rest with a simple exercise. I was face down in two feet of water. Fin as hard as possible for 30 seconds and then go to your backup secondary.

I would suggest that you try this drill.

I may well try that. Please explain how this relates to the safety of a CESA. You are not supposed to fin as hard as possible (you'll ascend too fast probably) and I'm not sure what going to my octo has to do with CESA. I probably just don't understand the reasoning and it may well be sound.

It seems recently there has been a comparison between novice divers who may do something wrong during CESA, such as hold breath or reg out of mouth. Needless to say, I have never done these things. Are those against an advanced (not AOW.....) diver doing a CESA saying there is a real risk of barotrauma doing it from 30' during a 30' dive? If so, I'd like statistics. As someone pointed out "the process of drowning begins" when the reg was out. Is this going to happen to me?

Someone pointed out that instructors get DCS (doing CESA I suppose) more than others. I've heard this as well and it makes sense. Though an instructor may do this many times in a row, the instructor is obviously doing it correctly. But there is a lot we don't know about DCS.
Question, as I may be slack on something-- My job during the vertical CESA skill in the ocean was to supervise all the students at depth while the instructor CESAd them one at a time. Is the instructor also doing a CESA each time while going up with each student? Or is it just the many ups & downs that may lead to barotrauma? Admit, I never watched that closely--just out of the corner of my eye.

Someone else pointed out that it is a skill sanctioned and required by the agencies. Thus practicing it once and a while would SEEM to be the correct thing to do. Otherwise, why is it "skill"?

It was suggested I should use my pony on a 30' dive. Haven't heard of many doing that.

The few of us can probably go back & forth on this for a long time. I don't believe I am someone who feels that I can become slack on the preventative measures to avoid OOA because a do feel comfortable doing a CESA. But will concede that many divers may. The same logic as drivers taking more chances because seat belt laws became mandatory decades ago. I like to think I still drive as carefully as when I didn't use the belt before the '80s.

 

[KenGordon]

If I aa relative of mine died after a panicked OOG ascent, and I found out you told them they had no safe option without an alternate air source and were going to die under those circumstances, you can you would lose that lawsuit big time.

But it is ok to have a student you taught have a panicked OOG ascent? What is the cause of the death? Not managing to bolt to the surface or needing to bolt to the surface?

Being under the water with only one source of gas is not safe. In the event you loose that you have a high chance of injury. Should I instead say “don’t worry about where your buddy is, or how much gas you have, you can always do a CESA”?

I guess it all depends on what we consider safe. 1 in 4 chance of injury? 1 in 50? 1 in 1000?

Running out of gas is totally unacceptable. According to the BSAC numbers 21 people died over 11 years in 176 OOG incidents in the U.K. About an 11% death rate. That is about the same as the death rate for attempting suicide (at least in Australia Lethality of suicide methods).

Even if OOG is under reported 10 fold we are still looking at a 1% chance of death. That isn’t too clever is it?

 

[The Chairman]

Are we saying that a properly done CESA (as required by the training agencies) is too dangerous to be practiced by advanced divers to maintain master of this basic skill?

Got a mouse in your pocket? I caution my students to not try a vertical CESA without an instructor present. Yes, it's my opinion that they are way to dangerous to do on your own.

Gas planning is wonderful,

Gas planning alone won't keep you from being OOA. Limits. It's all about the limits. If you and your buddy are checking each other's gas supply at regular intervals, then the chance of going OOA is moot. Since I've started diving with an SPG around the turn of the century, I have yet to run out of gas, much less to do a real CESA. In addition, none of my buddies have gone OOA or have had to do a CESA either.

 

[The Chairman]

Someone pointed out that instructors get DCS (doing CESA I suppose) more than others. I've heard this as well and it makes sense. Though an instructor may do this many times in a row, the instructor is obviously doing it correctly. But there is a lot we don't know about DCS.

It's not just simple DCS. I know of at least a half dozen instructors who no longer teach because of repetitive injuries from doing CESAs. Most of these instructors have ear issues like equalizing issues, vertigo and the like. I know of at least another half dozen or more who did have simple DCS either the day they had done multiple CESAs or the very next day on a subsequent dive. It's not healthy, and we're playing DCS Roulette every time we do this. That and as an instructor I feel I should be setting the very best example. Bouncing up and down like a yo-yo is simply a horrible example for your students to see. We want them to emulate us, and they will.

 

[lowviz]

I may well try that. Please explain how this relates to the safety of a CESA.

Job #1: Go home to your family at the end of the day.

Never exert yourself past a point that you can't handle. Don't try that exercise at CESA depths.

 

[northernone]

Got a mouse in your pocket?

...no, I'm just glad to see you.

I'm on board with avoiding needless yo-yo profiles as an instructor, particularly if done with puppy mill class sizes or exceeding sensible ascent rates.

As a diver I really love knowing I don't need functional SCUBA gear to stay alive and healthy (recreational profiles). I want my students to know this as well because it's what the mainstream agencies teach as required and calms people.

"If you have a catastrophic gas loss and a buddy separation you're dead" might be a memorable way to encourage gas management but artificially limiting one of the tool a diver has to survive (CESA) seems to be doing them a misfavor. I'd rather a calm CESA than a panicked weight drop ascent. (Of course plan A is taught as well)

Thats why I introduce the standard skills to my students and expect mastery. It's also why I practice them regularly so I can practice what I preach... same as rescue skills or any of the others the agencies advocate commonly.

I'm not much of a rule follower but the training methods have been paid for in blood and I'm not going to start tossing skills away without someone higher up the food chain saying so and convincing me why.

Cameron

 

[TrimixToo]

Got a mouse in your pocket? I caution my students to not try a vertical CESA without an instructor present. Yes, it's my opinion that they are way to dangerous to do on your own.

Gas planning alone won't keep you from being OOA. Limits. It's all about the limits. If you and your buddy are checking each other's gas supply at regular intervals, then the chance of going OOA is moot. Since I've started diving with an SPG around the turn of the century, I have yet to run out of gas, much less to do a real CESA. In addition, none of my buddies have gone OOA or have had to do a CESA either.

This would seem to assume equipment that is working. The other reason to go OOA is a malfunction that drains what's left in the tank (which is guaranteed to happen when you need it least). I have seen an LP hose failure from the surface. It's just amazing how fast the air comes out. 100' or so of ocean just turned to froth.

My original training included doff and don, with an ascent in between the two, and IIRC it was an open water test skill at the time. I last tried this out a few years back in about 30' of water in a dry suit, with a doubles, back plate, and wing, just to be sure I could still do it. I was reminded about just *how* much air comes out as you ascend--it's always way more than I anticipate. It was the first time I'd done it in a dry suit and I had to flare to get the suit to vent fast enough so the ascent did not accelerate too much. I'd hate to have to do this any deeper than 60' or so, but reasonably confident I could do it from 100'. From 200' would (a) be really hard if it were even possible and (b) bend me like a pretzel, most likely.

I focus my planning and execution energy on never being OOA but I am willing to admit it could happen if unforeseen circumstances arose. For this reason, I find CESA a reasonable tool for me to have in my tool belt. That does not mean I have a strong view about teaching it, one way or the other. I have never had to do one outside training and practice, and have only ever seen one.

 

[TMHeimer]

Job #1: Go home to your family at the end of the day.

Never exert yourself past a point that you can't handle. Don't try that exercise at CESA depths.

I must be really dense. What does overexerting yourself have to do with a controlled CESA ascent?

 

[TMHeimer]

It's not just simple DCS. I know of at least a half dozen instructors who no longer teach because of repetitive injuries from doing CESAs. Most of these instructors have ear issues like equalizing issues, vertigo and the like. I know of at least another half dozen or more who did have simple DCS either the day they had done multiple CESAs or the very next day on a subsequent dive. It's not healthy, and we're playing DCS Roulette every time we do this. That and as an instructor I feel I should be setting the very best example. Bouncing up and down like a yo-yo is simply a horrible example for your students to see. We want them to emulate us, and they will.

I figured there were ear and other issues since I have heard stories about it. Actually, the instructors at our shop that talked about CESA did mostly mention ear problems. So I agree with all that you say, but of course we're talking about instructors on courses. Do you also figure that such risks are there for someone doing a CESA twice a month?
I was asking before if the instructor always did a CESA when accompanying the student doing his/hers? If so, why?--to show the student that the instructor is CESA-ing along with the student?
Without re-reading back a ways, when you say that students seeing instructor yo-yo on multiple CESAs sets a bad example to follow, do you support eliminating it as a skill to be taught?
I see your point and don't disagree. Perhaps one answer would be to allow assistants to do some of the vertical ascents? Any other ideas to keep it in as a skill while not setting a poor example?
Perhaps just doing it horizontally in the pool only and telling students it would be easier vertically due to the pressure change and more air available/lungs feeling fuller, etc. as you ascend (which we would tell them at the pool now anyway)?

 

[aquacat8]

I can’t believe that instructors are still required to teach CESA in a manner endangering their own health. When an orca was chewing up trainers it was covered up a while, but eventually resulted in an OSHA lawsuit, a movie, and awareness of the plight of workers and orcas. Are agencies not opening themselves to a class action lawsuit here?