ESAs, EBAs, Air Sharing, & Alt Air


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Posted by Karl S. on September 25, 2002 at 11:13:54:

In Reply to: Re: Casino Point/some details posted by Ken Kurtis on September 24, 2002 at 11:29:39:

I have D/M-ed for SSI & PADI and have taught for NAUI, and all 3 organizations teach and drill ESAs [Emergency Swimming Ascents]. It is a fairly universally taught and drilled procedure. I cant speak for YMCA scuba.

Some SSI shops also teach and drill EBAs [Emergency Buoyant Ascents]. I know of one that does and one that does not. NAUI emphasizes dropping the weight belt for danger situations, and drills it at the surface, but not at depth, from my experience. PADI like NAUI drills it at the surface only, again from my experience.

Air Sharing is the main emergency procedure that currently gets a lot of emphasis by all the scuba agencies, and there are numberous drills in the pools and the open water for it.

Alternate Air gets mentioned in class, but few if any dive students ever see a pony bottle until they start diving with a club or group.

"Why Teach ESAs?" was a question raised in some of the replies to Ken's post. That is a valid question, especially in light of the fact that buddy breathing is virtually no longer taught by any of the agencies, and EBAs are rarely taught. In other words, scuba is a still evolving science, and agency requirements change.

Teaching ESAs is when there is a high potential for catastrophic failure to occur for a student. Embolism is what we most fear during this drill. Given that danger, I am somewhat surprised that this drill is so universally taught and required by the agencies.

A scuba instructor has to watch carefully to see that the student is truly exhaling continuously during the ascent. If the student looks like he/she is holding his/her breath, the instructor has to restrain the student from continuing the ascent. In that case, the drill is normally aborted and tried again later.

ESA drills when performed successfully require students to deal with buoyancy, with continuously exhaling on emergency ascent (which is a critical skill), with awareness of SPG air pressure, and with buddy skills and buddy awareness.

In addition, if the new diver ever was in a situation where he/she needed to do an EBA [buoyant versus swimming], since this skill is virtually never taught at depth in the open water, hopefully he/she will remember to exhale continuously as experienced first hand during the ESA training.

I believe in thoroughness in training and in over-training. I wish all student divers were required to possess a pony bottle and taught how to use it, with that as the primary emergency procedure for OOA situations. But it isnt.

Short of that, since buddy skills in new divers result in a lot of lost buddies underwater, it seems to me that ESAs need to be taught and drilled during open water training. Sure, its dangerous.

Its also too bad in my opinion that EBAs are not universally taught as well. If a new divers has poor buoyancy skills and scuba dives negatively buoyant most of the time, churning up the bottom, like many do, then in the case of an OOA situation and ESA wont work, since the diver wont be able to swim up while negatively buoyant. Thats when an EBA would be the only reliable self-rescue.

Yet EBAs have largely fallen by the wayside during diver training.

If ESAs also fell by the wayside, then diving would probably become more dangerous for many more beginner divers. Conditioning is required for these drills to work in real life. Conditioning is needed in order for divers to exhale continuously on scuba during emergency ascents, whether EBA or ESA. They wont learn it unless it is drilled in the open water.

In technical diving, which was mentioned by someone in reply to Ken's post, neither EBA nor ESA is a feasible alternative. Only gear and gas redundancy is available as a fallback for emergency situations during technical diving. Sure, you could change all basic scuba instrution to require manifolded twin 40 cu ft tanks and two of everything, instead of the current single 80 cu ft tank that is common protocol. But basic scuba would then sure get really expensive, too expensive to be an economic reality for most people and for most dive stores.

So overall, I believe we are stuck with teaching ESAs for the present time. And I myself would be a lot more comfortable if we also universally taught and drilled EBAs and Alt Air [pony bottles] in addition.

There is good and bad that goes with ESA training in open water classes. Hopefully the good outweights the bad. And if not, if ESAs eventually become viewed in the same negative light as have EBAs and buddy breathing, then ESA training will probably eventually fall by the wayside just like buddy breathing and EBAs have. My view.

I regret that a dive student has died during a training class somewhere in our state of California. Absent further medical information it is not possible to determine whether the cause of death was an embolism during an ESA or else a heart attack from exertion during an ESA or some other reason. We will have to wait and see what Ken finds out and shares with us, before we can logically implicate the ESA drill further.

/s/ Karl S.
NAUI Active Status Instructor
TDI Technical Trimix Diver
PADI Divemaster


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