Diver drowns in guided cenote dive

[Storker]

Accident analysis related to cave dives is part of cave diver training.

And the analysis goes like "just say no, he didn't say no, that's it"?

 

[John C. Ratliff]

Sorry John this is wrong. When they enter the cavern they are IN the cave already. Within sight of daylight is referred to as the "cavern zone" of the CAVE. This is an important difference to understand as where the cavern zone is located can change suddenly to full cave zone by something as simple as clouds rolling overhead.

in this case, you really don't have a workable "cavern" definition.

SeaRat

 

[JohnnyC]

And the analysis goes like "just say no, he didn't say no, that's it"?

No. But the cut and dry cases are very obvious once you know what you're looking for, and knowing what to look for is a large part of what you learn. There's no great mystery or learning experience here.

People are sounding like that canadian journalist guy whining about Carlos Fonseca.

 

[Jack Hammer]

in this case, you really don't have a workable "cavern" definition.

And that's what a lot of people have trouble understanding. It's also why a cavern dive can not be conducted at night, because at night the cavern ceases to exist.

 

[John C. Ratliff]

I haven't been intrigued by what JohnnyC and others here have been saying about "accident analysis" already being part of cave diving training. So I did some research, and this dates back a number of years to Sheck Exley's work, and the "rules" he put together. This work was updated just prior to Sheck's death by him, and there is a great write-up on it. Here is the last section on that write-up:

*
A FINAL WORD
Fatal dive accidents frequently have multiple and complex, often interconnected, root causes. While each accident has unique qualities about it – in part because of the individuals involved – most accidents can be characterized as a chain of events that lead to disaster.

This chain of events very often starts with a minor challenge… a failure in communications, a broken strap. But like dominoes, one event triggers something more serious, and this in turn results in more escalating calamities until all the dominoes have all fallen down. Technical divers need to get pretty slick at removing a domino early on and breaking the chain. Often something as simple as calling a dive early, before anyone gets close to the edge, can change the outcome radically and turn a nasty epiphany into a positive learning experience.

Unfortunately, the more challenging the dive and the greater the distance between it and mainstream sport-diving limits, the more risk is involved. This is the price we have to pay to experience something out of the ordinary and truly exceptional. No amount of training, experience, equipment or good luck will completely mitigate this risk, and sometime sooner or later, many of us will get our fingers burned. We do well to remind ourselves often that if we participate in technical diving, there is always a risk of serious injury or death.

Accident Analysis

I will let this sink in for a while, then comment further.

SeaRat

 

[oya]

I will let this sink in for a while, then comment further.
SeaRat

The author of this text is @Doppler on this board. See post #9 in this very thread.

The book which he discusses, The 6 Skills, is something of a canon read for a new tech diver.

You might also note a passage a bit earlier:
"The simplest way to stay out of the statistics column is to have a realistic grasp of your personal limits and the limits of your gear and then to stay well within those limits. It’s that simple; however, most of us need some help being honest and well-informed about where our limits actually lie."

 

[MXGratefulDiver]

We have no information about how long the diver was missing before it was noticed. We only know his absence was noted a half hour into the dive. We have no indication as to when he was last seen before that. In theory, it could have been only seconds.

Therefore my comparison between Cenote diving and Discover diving. In both cases, right or wrong, people are entrusting a paid dive pro to protect them from their own ignorance. Consider what could happen on a Discover dive if the DM lost track of their client for "only seconds". There should be some process that allows the DM to maintain "control" of their clients at all times. Whether this means limiting the number of clients to no more than two, whether it means positioning the divers so that the guide brings up the rear instead of the front, whether it means having two guides ... one in front and one in back. However, losing track of a client for "only seconds" can clearly be fatal when putting them into an environment where they are so lacking in training and experience that they can, through ignorance or willful disobedience, place themselves in fatal danger within that short span of time.

... Bob (Grateful Diver)

 

[The Chairman]

JohnnyC and DocNet

At least I can spell your name correctly

If you're going to throw in "spelling", then make sure you have been impeccable with everyone else. That's not the case here.

Here's the thing; you are not offering anything in your "analysis."

Again, this is not true. We've been constantly telling everyone that they need to obey the basic tenets of cave diving and this would not happen. You can tell us how wrong we are, but that just makes us discount your opinion even more. Bob has been nice enough to post these tenets... I was hesitant, since I don't want anyone to mistake this as a substitute for training. That's probably the one rule I see violated most often.

1. Always dive within your training - for purposes of this discussion, that means if you aren't trained for overhead diving, don't do overhead diving.
2. Maintain a continuous guideline to open water - in this case, if he was in the cave zone, there wasn't a continuous guideline. At some point there would be a jump gap between the cenote line and the line into the cave.
3. Reserve two-thirds breathing gas for the exit - the infamous "rule of thirds" ... in this case, this probably didn't happen
4. Never exceed the maximum operating depth of your breathing gas - this one was not applicable in this case
5. Use equipment appropriate to the conditions - in an overhead environment that would mandate some form of redundant air supply and a minimum of two functioning lights

 

[John C. Ratliff]

The author of this text is @Doppler on this board. See post #9 in this very thread.

The book which he discusses, The 6 Skills, is something of a canon read for a new tech diver.

You might also note a passage a bit earlier:
"The simplest way to stay out of the statistics column is to have a realistic grasp of your personal limits and the limits of your gear and then to stay well within those limits. It’s that simple; however, most of us need some help being honest and well-informed about where our limits actually lie."

Here is a quote from that blog that @Doppler wrote:

Exley’s ideas had gained general acceptance and had stood for several years unchanged and unchallenged but shortly before his own tragic death in April of 1994, exploring a deep cave in Mexico, Exley revisited his work on accident analysis and expanded his safety procedures to reflect massive changes in the world of technical diving and to accommodate the widening appeal of technical diving with divers outside a cave environment. In addition, a veritable who’s who of advanced diving adding their input and suggestions to Exley’s framework, and the results now, almost a generation later, is a Risk Management Process intended to help prevent unnecessary deaths, and to help drive home to a growing audience of enthusiastic divers, all ready and willing to push the envelope, that while technical diving is fun, it is totally unforgiving of the foolhardy.

Risk Management is the identification, classification, avoidance and mitigation of risk. In order for it to work, it requires honest and detailed answers to some straightforward questions and following some common-sense guidelines organized into eight categories: Attitude, Knowledge, Training, Gas Supply, Gas Mix, Exposure (the combination of Decompression and Depth), Equipment, and Operations… let’s take a look at them.

Please note that this comes from his updated book, Staying Alive. This is getting towards the Risk Management principals and models of accident analysis that I have been advocating here.
About Risk Management

Now, let me address in more detail who is "qualified" to talk about accident investigation for this cavern/cave diving scenario. If you will remember a while back, there was a spectacular accident of the space shuttle, Challenger, whereby a failure of the solid rocket booster O-ring ignited an explosion that took down the shuttle, killing all the astronauts. The day previous, Thiokol engineers had provided 13 charts which they thought would convince the administrators that the launch should not take place under those cold conditions. The subsequent hearings included the aeronautical engineers and others associated with the launch, each providing information about these O-rings and whether it was or was not the cold temperatures that caused the accident. It was not these engineers, but a physicist named Richard Feynman who provided the illustration, using a piece of O-ring, a clamp and a glass of ice water, to show that the O-ring in question did not have the resilience to work under those circumstances:

...I take the clamp out, hold it in the air, and loosen it as I talk: "I discovered that when you undo the clamp, the rubber doesn't spring back. In other words, for more than a few seconds, there is no resilience in this particular material when it is at a temperature of 32 degrees. I believe that has some significance for our problem."
Tufte, Edward R., Visual Explanations, Images and Quantities, Evidence and Narrative, Graphics Press, Cheshire, Conneticut, 1997, page 50.

He had no aeronautical experience, but he had insights that proved critical to this particular accident.

From what I can see here, some of you have a "group think" situation going on here that is insular, and keeps you from even looking at outside information. You also seem to be even behind your own field's information, using the "Five Rules" for cave diving, when it has been updated to eight principals of Risk Management as it applies to technical and cave diving.


SeaRat

 

[The Chairman]

Divers either lack the skill to be in these environments altogether or they are just experienced enough (I'm looking at you OW instructors) to think the rules don't apply to them anymore.

Reggie Ross, a Cave instructor was a part of my IDC many, many years ago. He made a comment which really stuck with me. It went something like "If I pull someone dead out of a cave, it's quite likely that they're an OW instructor who's had no training in a cave". I booked my cavern class right after this. It wasn't really a scare tactic, but it was a sobering statistic.