Accident Analysis (take two)


Enroll in any high-risk, high-stress endeavor, and the chances are that one of the first topics your instructor will throw into his or her opening conversations with you is how many ways you can kill or hurt yourself doing what it is you just signed up for. The first steps in just about every training program in the “adventure” category of things to do – from flying a plane to shooting a gun (at targets or bad guys) or climbing rocks or heli-skiing – will walk the activity’s newcomers through potential pratfalls. It’s a kind of universal mantra: learn from the mistakes of others.

Diving courses, well, certainly ones aimed at imparting skills for technical diving, work in a similar way. The politically-correct term used in the industry is Accident Analysis, and the framework for the AA modules I have been taught, worked with, or developed and written over the years follows closely the one first constructed and then refined for teaching cave diving. In its shortest form, an Accident Analysis module boils down to three stages: here’s some advice about what works, here are some examples of people ignoring that advice, now can we agree that they were stupid and that we will try not to follow their example.

For the record, here are three real-life scenarios that got people killed. I share these with tech students. See what you make of them.

Scenario one: August, 2009. Three experienced sport divers attempted a deep dive off the coast of California. The participants were a dive-store owner, his friend, and a 22 year-old shop employee and DM. Although the trio had done similar dives before, none was certified beyond sport-diving limits. The dive shop involved did run tech programs, but they were overseen by a third-party instructor. Worth noting is that this individual was NOT part of planning the dive in question and was apparently not involved at all. By the way, the dive was planned to be around 60 – 65 metres using air as back-gas. It turned out that the actual dive’s depth exceeded the plan at 70 metres plus. During ascent, the “team” lost contact with each other and the 22 year-old man was seen drifting away from his dive “buddies” and was sinking. After some time, his body was found on the surface.

Scenario two: November 2009. Two divers attempted to dive Eagles Nest on CCRs. On a previous occasion, the pair had been taken to the “cavern” area of the nest by an instructor teaching them a course on CCR which they did not pass. For the record, one must apply a very liberal definition of Cavern to describe any part of the entrance to Eagles Nest, an extensive and very deep (80 metres plus) cave in Hernando County, Florida. Also for the record, neither man was cave certified, nor was the instructor who had previously taken them to the cave for training dives, a cave instructor. During their ill-fated final dive together, the two CCR divers had opted to use a diluent in their rebreathers was hot for the depth they attained (reportedly one containing 18 percent oxygen). If this were the case, it would have made impossible at depth controlling their setpoint (partial pressure of oxygen) at recommended levels of 1.2 or 1.3. Also, a meaningful diluent flush, cell test would have been impossible. At some point, approximately 170 metres from the cave’s entrance area, one of the divers experienced difficulty and died. His body was recovered in one of the deepest sections of the cave some time later by a team experienced in deep-water body recovery.

Scenario three: In mid-November 2008, the bodies of two divers were recovered from Wayne’s World (aka School Sink), Pasco County, Hudson, Florida. Wayne’s World is considered an advanced cave dive yet only one of the buddies had ANY overhead training, and that was only an Intro-to-Cave card – well shy of what’s recommended to dive this site. The other diver carried only an Advanced Open Water certification. Both were wearing traditional North Florida Cave Kit with decompression gas. Recovery divers discovered both bodies within 80-90 metres of the cave entrance. Their bodies were separated by approximately 30 metres distance. One was found at a depth of approximately 14 metres with his oxygen decompression gas deployed (oxygen is considered highly toxic if breathed deeper than around 6 metres). The other was deeper in the cave, dead on the ceiling showing signs of distress. During inventory of the dead divers’ equipment, this diver was found to have his isolator closed with one cylinder empty and the other containing at least 3500 psi.

Here are the questions I use to begin the analysis process in the classroom.
Where did logic chain begin to break down?
What simple guidelines seem to have been ignored in these cases, and how might ignoring them have contributed to the seriousness of the situation these people found themselves in?
In all three cases outlined, whom do you feel should shoulder some responsibility for these deaths?

 

Of course, by its nature, this exercise is speculative since the process asks us to form conclusions based on a sandwich made from a couple of slabs of conjecture and a thin layer of fact. There is also a complex moral issue with us forming a judgment about someone’s behavior – which inevitably happens – without their input during our deliberations. After all, there may be rectitude in their behavior – although on that last point, experience does tend to suggest there are no fixes for stupidity.

 

However, all that aside, the exercise serves a purpose which is not to allot blame but rather to identify errors, understand how easy it is to mess up and from that deductive analysis, avoid repeating the same mistakes ourselves.

There’s one other shortcoming. Between you and me, I dislike using the word Accident to describe many of the examples we use to point out the kind of behavior that results in diver deaths.

What is an accident?
One definition of an accident is “any unplanned event that resulted in injury or ill health of people, or damage or loss to property, plant, materials or the environment or a loss of business opportunity”.
That’s OK as far as it goes. Certainly unplanned seems to be the pivotal point, but it begs some further investigation… and definition surely. Let’s take for an example scenario three above.
It’s well known that diving in a cave without training is a poor choice. Did the two guys who died know that diving without training, experience and kit in a cave was a poor choice? Sure they did. There’s a bloody great big sign to remind them at the cave entrance. They planned to dive ignoring that fact, and I’d wager the general consensus from fellow divers would agree as inappropriate using a definition that includes the term “an unplanned event” to describe their actions.
Given the circumstances of their dive, their behavior was risky: they took a risk and their calculations – whether conscious or not as to how likely their choice was to backfire and kill them – was incorrect. They screwed up, assuming naturally that their intention was not to kill themselves. Think about this: One guy had around half his back-gas available. All he had to do was switch regs or reach back and check his isolator. Yet signs at the site of his death indicated he drowned.
Is deciding to take a risk and miscalculating its inevitability an accident? Is ramming into the back of a parked car at high-speed with an alcohol level above the legal limit for a driver – whatever that limit may be – an accident? Surely it’s recklessness, carelessness or criminal. What do you think?
The Brits use the term “death by misadventure.” For the record, the definition of this phrase in Webster’s is “a death due to unintentional accident without any violation of law or criminal negligence. Thus, there is no crime.”
Death by misadventure does have a nice ring to it: no blame, just a couple of guys out on a lark that went wrong. Is that how you see scenario two, or is there more to it.? Is there some level of culpability, negligence?
A buddy of mine tells his students that cave diving is deceptively easy.

“Anyone can swim to the back of a cave,” he says. Another buddy tells his students that “Even an open-water diver can make a dive to 60 or 70 metres.” They also add that their statements are only true until something goes wrong. In a pear-shaped world, it’s finding the way out from the back of a cave or getting back to the surface intact from 20 storeys down that presents problems.

 

When things go wrong underwater, the fundamental skill becomes survival. In diver training, this is broken down into three major tasks:
• control the natural fight or flight (or freeze) response
• suppress panic
• work on getting your ass back home (This latter skill requires critical decision-making, physical and mental actions involving some level of multi tasking, which some people can do, and some cannot.)
The ability to react appropriately when things fall apart is an acquired skill even for those who have some natural abilities and the skills to survive. It takes knowledge backed up by experience and practice. How much of each is a hugely debatable point, but I believe the diving community as a whole agrees that it takes more experience and practice than one can gain during the average technical diving class… even when full knowledge of what to do and how to handle the situation has been taught.
Well, that’s a shocker, isn’t it? We certify divers to do dives but we believe they may need more experience and practice before they can survive something going pear-shaped!
If this were the case, our beaches would be littered with the dead and injured and clearly they are not. Most people leave a dive class – regardless of whether it is a sport diving or tech diving class – with a full understanding that what they just earned is an OK to go out into the real world and gain experience and practice, gradually. They have the knowledge to do so well within the limits of their training. And that is the key… within the limits of their training. Without training or with a disregard of what that training taught, all bets are off. They have no knowledge and are unlikely to live long enough to gain wisdom.
So what is the bottom line, take-home message from Accident Analysis?
I’ve always reckoned it to be the advice to take things slowly, to be cautious, and to stay within the boundaries of your comfort zone, which are the actions of a wise diver. What does Accident Analysis say to you?

3 thoughts on “Accident Analysis (take two)

  1. Thanks Steve, another great thought provoking article. As you know I am doing some work in this area and recently read an interesting article looking at aviation Accident Analysis by Dr Sidney Dekker. This article take a slightly different tack and asks investigators to consider the circumstances of the person involved in the accident (similar to the point you were making above) The direct link to the PDF is here http://www.lusa.lu.se/upload/Trafikflyghogskolan/TR2002-01_ReInventionofHumanError.pdf. Well worth a read if you are interested in this subject.

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