CESA over Shared Air Ascent: Which is Best

[MauiScubaSteve]

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

So far, six people feel it is better to blow off ascent rates and safety stops than to do a normal ascent, while sharing air with a buddy. For the life of me, I can't understand how that would be better.

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.

At 25' max depth, you could dive for over 2 hours and still not require a safety stop on most tables. If you know how to do CESA, you could easily take over 30 seconds to rise 25'; I can exhale completely and then wait for over 20 sec before inhaling (just did it). A properly done CESA can easily be done at modern ascent speed (30fps) in your case.

Per the parameters of your situation; those voting for CESA were not saying they would blow off ascent rates or required safety stops. You are putting words in peoples mouths.

Again, I question your training and terminology; a normal ascent is just that, the diver ascending normally breathing from their tank. An alternate ascent with buddy is not a normal ascent.

Your situation is also silly; if you are with a competent, accessible buddy there would be no need for CESA; perhaps the 6 votes are just people f#@king with you because you started a silly poll.

 

[MauiScubaSteve]

Seriously? Padi ranks CESA above buddy breathing? With buddy breathing you still have an opportunity to do a safety stop. Good grief.

From the 10th post on this thread.

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.

 

[MXGratefulDiver]

I suppose the thread is about cesa vs shared air. I'm shocked that even 6 out of nearly 100 would prefer the cesa over sharing air.

I'm not surprised at all.

Self-sufficiency means different things to different people, and there are always those who distrust anyone else to be competent to help them.

I'd be willing to be the majority (if not all) of those who chose CESA would identify themselves as solo divers ... even if they do occasionally dive with a buddy.

... Bob (Grateful Diver)

 

[24940]

I cant imagine why wone would choose CESA with an accesible competent buddy that had adequate air. That last part takes it beyond your poll constraints.

[EDIT]
For the purpose of this poll, assume :

You are diving with a competent and accessible buddy

Maintaining an adequate gas supply is one of my criteria for defining what a 'competent buddy' is. I should have been a bit clearer, but what I really wanted to know was how many people felt CESA was a better option to a shared air ascent.

A

Your situation is also silly; if you are with a competent, accessible buddy there would be no need for CESA; perhaps the 6 votes are just people f#@king with you because you started a silly poll.

Silly? Did you see the quote in my original post? Here it is, again:

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.

That quote came from an instructor and I wanted to see how prevalent such thinking was. He was serious.

I used 25', because the term he used, "reasonably shallow depths", is entirely ambiguous and subjective. For me, the definition would mean 40'-70', but I used 25' because I believe most dives are in excess of that depth.

So, with the bold, underlined portion of your post I quote, I say thanks for answering the simple question simply. The rest of your comments are just off topic static in terms of this thread. Valid point in another context, but not relevant to the point of the poll.

 

[Darnold9999]

I'd be willing to be the majority (if not all) of those who chose CESA would identify themselves as solo divers ... even if they do occasionally dive with a buddy.

... Bob (Grateful Diver)

Guilty, and I am pretty sure you are right re the others as well.

I'm not surprised at all.

Self-sufficiency means different things to different people, and there are always those who distrust anyone else to be competent to help them.
... Bob (Grateful Diver)

and IMHO at 25 feet the risks of something going wrong on an air share with an instabuddy are far higher than something going wrong on a 25' ascent. The day I can't swim up 25 feet in complete control with no air is the day I give up the sport.

As you get deeper the calculus changes rapidly.

 

[missitnoonan]

I actually think I got that question wrong on my OW test. Didn't make any sense to me that a CESA would be ranking over buddy-breathing.

I think it really comes down to your buddy. My buddy on most dives happens to be my wife, and the odds of me being more than an arms length away are about 0%. I also trust the two of us to handle a situation together calmly. But if we're talking about a guy I just met on a boat dive? I'm not the most experienced diver and I try to stay with my buddy, but what am I supposed to do if they're swimming behind me and jet off?

 

[ClayJar]

but what am I supposed to do if they're swimming behind me and jet off?

Grab them by the fins, pull one off, and lead the rest of the dive.

 

[24940]

and IMHO at 25 feet the risks of something going wrong on an air share with an instabuddy are far higher than something going wrong on a 25' ascent. The day I can't swim up 25 feet in complete control with no air is the day I give up the sport.

Once again, this thread is not about diving with the incompetent, untrained or unwilling. It's not about instabuddies, it's about sharing air with a competent buddy or doing CESA and which makes better sense from a safety standpoint.

As you get deeper the calculus changes rapidly.

Calculus? What kind of equations are you running?

 

[SparticleBrane]

As you get deeper the calculus changes rapidly.

What's important? The change, or the rate of change with respect to depth?

 

[Darnold9999]

That is not a reality of diving, in my experience. It's a reality of poor training or lazy divers.

It's not about perfection, it's about attentiveness and responsibility.

or choice - can't say I'm lazy or untrained. Well you can say it but I will object.

I don't see anyone arguing against having CESA as a tool, I'm certainly not. That has nothing to do with the thread or the poll. Simple question: Which is preferable under the given scenario?

The response that this was a 70's attitude generated my response. In the 70's we had CESA and buddy breathing as a choice. I developed a comfort level with CESA at that time. Nothing I have seen since has changed my mind about using it fairly early in the problem solving chain and at 25' IMHO it is a safer choice (for me) in most (not all) situations than an air share - particularly with an instabuddy.

There is a school of thought that eliminates CESA as a tool - you figure it out under water til the bitter end. For tech divers with an overhead this is a good mind set, for rec I personally don't agree, I will problem solve until my ability to use CESA is about to disappear, at that point, if the problem is not solved or obviously about to get solved, I'm gone. In my limited understanding the very definition of rec diving is based on CESA - if it's not possible to CESA then you need additional training, hardware and protocols.

So far, six people feel it is better to blow off ascent rates and safety stops than to do a normal ascent, while sharing air with a buddy. For the life of me, I can't understand how that would be better.

Who said anything about blowing off ascent rates and at 25 feet, yep, I would blow off the safety stop in an OOA situation in a heartbeat. At that depth why are you even worrying about a safety stop unless you are returning from a deep dive?

It's better because an air share has significant risk that something will go wrong, particularly if you haven't practiced recently, don't know your buddy, haven't tested their alternate or any number of other quite realistic scenarios that will cause you to be unable to get air. Yes "proper" preparation will eliminate many of these, but I don't see that happening on every dive in the real world for most people. Have a look at the latest DAN survey to see how many people actually test their own secondary before every dive - let alone make sure their buddies is working. At that very shallow depth these risks are higher than the risk of CESA. Deeper that calculus changes.

Sorry, OOA at 25 feet - signal partner - go to my pony - check to see if buddy is offering me his reg - CESA. Not going to swim, get his attention, whatever. If the reg isn't in my face by the time the pony has failed I'm gone. No pony - signal partner - if reg isn't on its way immediately - CESA. Deeper - same thing, but I wouldn't be without the pony or some other source of air.