The deep air angle - split from Missouri Fatality

[Cave Diver]

Although I don't think that taking a formal training program is the only way to develop the necessary skill to do something.

No, formalized training is not the only way to learn something and in some instances it may not even be the best way. And as you've pointed out, many of the pioneers of the sport had little to no formalized training (Cousteau, Exley, et. al). They learned by trying things and pushing the boundaries of their knowledge and experience and gradually building up a reference base for what the limits were and eventually others learned from them.

On the flip side, some people that have formalized training, still aren't qualified to do some things. Training does not equal competency. This wide disparity in competency is what fuels a lot of these debates.

Diver A may take the formalized training, have 150 dives at that level and still be a complete Charlie Foxtrot in the water.

Diver B may have learned from a mentor, done 20 of those dives and be much more competent in the water.

So of those divers, who is more qualified to do them? A with their formal training or B with their competence?

The debate rages on...

 

[PfcAJ]

Actually, we kind of used to. I remember very clearly (well, that is to say, as clearly as I remember anything from 1972), my high school driver training instructor tutoring us on how to drive home from a party without getting into trouble when we'd had a couple too many. What we've seen since then is a radical change in mores, such that it is no longer socially acceptable to acknowledge driving drunk, although we see people driving buzzed all the time. I think a similar thing is happening in scuba: the cultural standards are changing because of the availability of trimix.

I happen to feel comfortable on deep air because I know from experience that I can handle the narcosis adequately. The difference is that, unlike the drunk driver, I'm not in imminent danger of killing anyone but myself if it should turn out that that assessment is faulty. (I usually dive solo.) My family, of course, would be affected, but I am well insured. (My non-group policy was purchased years before I became a diver, and I have more than adequate group coverage.)

So here's my question for you, PfcAJ: Why the heck is it any skin of your neck if I make the educated choice to dive deep air?

The we realized that driving drunk is always dumb. Thanks for the anecdote that makes my point a little Probably the only thing good about deep air is that its usually only one person that dies at a time, maybe 2.

Give it some time, we're already seeing a change for the positive with more and more agencies offering helium sooner. Its only a matter of time before deep air is relegated to something done in the past (like cave diving on a single, decompression on air, the j-valve, etc). Sure, people will still do it, but it will be far less common.

My beef is when people (agencies) think its ok to teach deep air. Teaching it pretty much says that its an ok thing to do. Probably the only thing good about deep air is that its usually only one person that dies at a time, maybe 2.

If you want to go dive deep air, have a blast. Please do it in a place where money and resources won't be spent on finding your body and the site won't be closed down (cave diving). People think that they "know the risks". I have a hard time believing that the fatality that spawned this conversation had a clue about the risks.

I still fine it extremely interesting that nearly ever death/serious injury that results from a dive past 100' also has an END over 100'. The correlation is real close to 1. Kinda like how cave diving accidents were analyzed, and contributory factors (including excessive ENDs) were found.

Senseless deaths bother me, esp when they are so easily prevented.

 

[PfcAJ]

This bolded comment implies a real lack of understanding of the situation. There is NO RAZORS EDGE! Instead there is a very wide depth range where diving air becomes increasingly more dangerous. Drawing the line at 100 ft is much. much too conservative for me, but if that what it says in the book that you follow...GREAT.!!!

I feel that for most of the conditions I dive in (open water, daytime, usually good visbility, relatively warm water) 200 feet is a better limit, but even then, I will infrequently exceed that on air, if there is something I want to see.

Just to follow up, that edge is a gray area, but by stacking the odds against you (by a lack of training, experience, improper equipment or gases, whatever) you darken that gray a bit.

When everything is going right on a dive, then its just gray, but when something goes wrong, that gray gets darker and darker. You better hope that gray area doesn't become a black line. Thats when we see fatalities or serious injuries.

I prefer to have fun on dives and not have a harrowing experience. The lighter I can keep that "gray area" the better.

 

[jvevea]

I still fine it extremely interesting that nearly ever death/serious injury that results from a dive past 100' also has an END over 100'. The correlation is real close to 1. Kinda like how cave diving accidents were analyzed, and contributory factors (including excessive ENDs) were found..

The correlation between number of firefighting units responding to a fire and $ value of damage caused by the fire is also close to 1.0. That correlation is roughly as relevant to how one ought to approach firefighting as yours is to the discussion about the safety of deep air.

 

[Sas]

I think many people in this thread need to take note of the expression: 'Correlation is not equal to causation; it is only a requirement for it.'

I'm not making a comment on whether deep air is bad or not, but just that you can't say 'X occurs when Y is a factor therefore Y causes X', it's just not a valid argument. Now Y might cause X, but it needs to be examined further. And I am always interested in reading detailed accident reports but so many of them seem to be just speculation, which makes it hard to determine what went wrong.

I don't care what other people do on their dives as long as it doesn't affect me. People need to set their own limits and it is a bit lame of others to judge other divers when their actions are not going to impact them in any way. I can totally understand people getting annoyed when sites are closed because of the stupidity of another diver but other than this people should make their own decisions.

 

[dumpsterDiver]

...I still fine it extremely interesting that nearly ever death/serious injury that results from a dive past 100' also has an END over 100'. The correlation is real close to 1. Kinda like how cave diving accidents were analyzed, and contributory factors (including excessive ENDs) were found.

Senseless deaths bother me, esp when they are so easily prevented.

I find it interesting that every SINGLE death and serious injury which occurs at LESS than 100 feet has an END Less than 100'. So what again soes this prove?

 

[dumpsterDiver]

......When everything is going right on a dive, then its just gray, but when something goes wrong, that gray gets darker and darker. You better hope that gray area doesn't become a black line. Thats when we see fatalities or serious injuries.

.

Have you experienced this (while on deep air) or are you parroting stuff you got from a book? Seriously, you go from "a razor edge" to shades of gray And then tell me I have to look for a black line.

 

[PfcAJ]

Think it through. There is a point in the progression of these fatal diver where whatever went wrong became too much for the diver to overcome. That is the edge I speak of (or black line. Same thing).

Let's take a hypothetical example. Diver gets entangled. Ok, not a huge deal. Except the diver is deep, impared, and on a limited supply of gas. By diving deep (more dangerous than shallow), impared (worse off than not impared), limited gas supply (oc scuba), the diver has lots of things working against him (approaching the edge or darkening the gray, same thing). Now, that entanglement is a life threatening issue. Incident pit, foot on the banana peel, pick your expression. Its the same idea.

Some things aren't really avoidable, such as limited gas (unless you're dcbc) and depth, but narcosis is avoidable. Why make yourself worse off? Why teach something that disadvantages the diver?

And fyi, I came to the above conclusions on my own, after making a mistake deep on air a number of years ago. I started looking at what deep diving deaths seem to have in common, which is high ENDs. Yes, I recognize that shallow deaths have shallow ENDs, but were talking about teaching someone a poor technique for diving deep.

 

[wedivebc]

Think it through. There is a point in the progression of these fatal diver where whatever went wrong became too much for the diver to overcome. That is the edge I speak of (or black line. Same thing).

Let's take a hypothetical example. Diver gets entangled. Ok, not a huge deal. Except the diver is deep, impared, and on a limited supply of gas. By diving deep (more dangerous than shallow), impared (worse off than not impared), limited gas supply (oc scuba), the diver has lots of things working against him (approaching the edge or darkening the gray, same thing). Now, that entanglement is a life threatening issue. Incident pit, foot on the banana peel, pick your expression. Its the same idea.

Some things aren't really avoidable, such as limited gas (unless you're dcbc) and depth, but narcosis is avoidable. Why make yourself worse off? Why teach something that disadvantages the diver?

And fyi, I came to the above conclusions on my own, after making a mistake deep on air a number of years ago. I started looking at what deep diving deaths seem to have in common, which is high ENDs. Yes, I recognize that shallow deaths have shallow ENDs, but were talking about teaching someone a poor technique for diving deep.

You know, some guy from Orlando comes on here and lectures us about how stupid we are for not using helium in our dive gas. Some places don't have a dive shop on every corner that sell a trimix card for $100 for a yearly unlimited fills. If someone around here wants helium they have to really look for it. It's around but not very accessible. Please don't lecture us about diving deep air until you understand the realities of diving in the rest of the world. Deep diving is a risk, yes diving deep air may increase that risk but unfortunately helium doesn't grow on trees outside Florida.

 

[Trace Malinowski]

While doing some research on this topic this evening, I came across some July 1992 technical diving fatalities Michael Menduno had profiled in AquaCorps:

The link for those who want to read the details of accidents is AquaCorps'

Menduno wrote:

According to a recent study of diving accidents conducted by Mano and Shibayama1, over 45% of the sport diving fatalities investigated were due to "lack of technique" or "reckless diving." Their conclusion is probably even more applicable to technical diving where there is little margin for error.

Fatalities

A newly trained cave diver got lost in the cavern zone after being separated from the team's line in zero visibility conditions at Alachua Sink and drowned.

An experienced diver wearing double overpressurized 72's "ran out of gas" while making his eleventh penetration dive on the Andrea Doria (240 fsw) . His partner who entered the water with a "half-filled" set of steel 120s -insufficient gas to safely make the dive- survived. Both were breathing trimix though neither was formally trained in its use.

Two weeks later another trained, experienced diver drowned after getting separated from the mainline during a wreck penetration on the Doria while the team worked as planned at two different places within the wreck. Though the trimix used to conduct the operation was a big safety factor, analysts on site believe the diver left the line to explore just a little further for artifacts before making his planned exit-contrary to the dive plan.

A very experienced deep wreck diver knowingly dived beyond the NOAA oxygen limits while conducting an enriched air dive on the Arundo (135 fsw), suffered an oxygen seizure and drowned.

An experienced 45 year old wreck diver suddenly lost consciousness during a 170 fsw air dive on the Chester Polling and drowned in the arms of his partner. The exact cause of his death is unknown.

A trained cave diver lost consciousness and drowned while making an enriched air stage dive at Devil's Eye cave system.

Two "untrained" recreational divers reportedly died in La Jolla Canyon attempting to beat their "personal best" depth records of 200 fsw which they made in the Canyon the week before using recreational scuba equipment. Their goal was to hit 250 fsw. Apparently neither of the divers had training or experience at these depths and had not done prior work up dives.

Apparently numerous fatalities occurred this summer in the UK and Europe involving technical level exposures. The majority of these accidents reportedly involved deep air diving in overhead environments. As of this writing we have been unable to get sufficient details to include these in this report.

Menduno goes on to say as he compares these accidents to violating rules of accident analysis:

The fact is that with the exception of enriched air training, there is presently no formal "standardized" special mix training programs or recognized safety standards in technical diving and only a handful of individuals (and few instructors!) have much experience at all.

This was 1992. Since then, mixed gas training has become both largely available and largely standardized. Much of the intelligent approach to mixed gas diving should be credited to GUE and the DIR community. There are many DIR trained divers who now teach technical diving for various agencies and preach team, reduced ppO2's, standard gases and gear and high quality skills in their courses.

The safety of trimix is probably a combination of the reduced narcosis, high-quality training, experienced divers, team diving, and more complex variables not often discussed such as the effects of the solubility of one gas on another.

However, air has also been used successfully for deep diving by highly trained and skilled sport, commercial and military divers and lest we forget was the world's first standardized recreational and technical diving gas used for decades before trimix became available.

The physiology of diving is not absolute. We may learn things in diving science tomorrow that may end the honeymoon phase of our love affair with trimix. Right now, it is our friend. Friendships sometimes end. Future costs of helium could lead to an increase in air diving as divers won't want to dive less nor quit making dives they enjoy. If cost were to become a major consideration, we can imagine that the safe operating range of air might extend back to the extended range depths with greater universal acceptance rather than condemnation.