Statistics: main cause of death with rebreathers

Mdemon

[In response to Abbo]

What you're really saying is CO2 hits are the major cause - keep scrubber duration/use etc out of it.

Over-using or using a duff scrubber won't kill you. The resulting CO2 hit will have a good go though!

I'd suggest further that CO2 hits can come from multiple situations - retained CO2 in someone working hard compared with dead scrubber, bypass, missing o-ring etc.

The only thing you can say with confidence is that CO2 hits happen and are more dangerous than initially thought. Following on from that, we can see that a BOV is a very, very useful piece of kit.

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sadave

Nah, I read it the same way...

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SteveJ

In deaths from 1997-2004, approximately 50% were diving solo. That's not a cause but it is a strong association.

teddy2005

Even the EDO-04 sole accident, the machine was in working order despite what was rumored...

jeff h

Yeah, 50% of the deaths were diving with a buddy, man is that dangerous!

The point is - No, it's not a strong association. As it was stated it only means you have exactly the same chance of living or expiring with or without a buddy. It means nothing as stated.

Now if only 10% of the population dives solo and they account for 50% of the death, well then that might be something.

Statistics are an evil mistress or a good marketing tool!

Dave O

That sounds like a very good topic for a poll! I just did a search, and there are none with the question "do you dive solo", or "how often".

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Gilles

I also believe this is possible. I call it conciousness allocation. Maintaining about 10% conciousness of PO2 under all circumstances, rather than the periodic switching of 100% your attention. This IMVHO, can be developed by practising via manual flight (don't want to go any further on that topic).

And a fair to poor buddy can cause a life lost. I'm supportive of the buddy process providing its purpose is served. When diving solo, I find my situational awareness to very switched on, and take much greater care due to the lack of comfort.
My worst mistakes have been forgetful errors, leading to hypoxia. I am particularly susceptible when at a new place, with new people, saturated with new surroundings and learning new things. . These sorts of things take me out of my comfort zone. Painful story another time.

The title of this thread is requesting an assessment of the main causes based on the stats. Hmm?, the only stat that there seems consensus on is that eCCr's tend to be involved in more incidents than mCCR's. On that premise, it seems the combination of leaky valves, and more involved piloting are effective mitigating factors.

That's about as far as the available stats are going to take you. I doubt this rather tenuous conclusion can be improved upon until more information is acquired (hopefully this is ongoing).

In my profession and industry, the HSE utilize a "swiss cheese model" to illustrate the barriers (process, competence, controls) that exist between an activity and an incident. Each barrier is imperfect (has holes due to people not following procedure/standard or due to inherent system weakness) and the idea is to align the barriers in a way so that the holes do not align, and for people to be more diligent in not creating the holes in the first place, and to intervene when one is being created.

With complete Rebreather incident info, and with the aid of technology and experience, it seems highly likely that major improvements in systems could be achieved providing barriers to common human errors, without re-creating the space shuttle. Perhaps much can be done by finding ways to affect peoples attitudes.

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caveseeker7

Don't know what EDO-04 accident you refer to, but in at least one of them the one way valves to the smaller bellows were defect and not working. On both units of the dual Rebreather setup. That the diver wasn't properly trained and diving shallow water probably didn't help much, either, but those components of his RBs were not in working order. The state police of the area posted an anlysis and warning including pictures on their website, the damaged/faulty valves were clearly visible.

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Mixaddict

I think the biggest reason people push their scrubber is not due to cost. I believe it is due to laziness. I believe people ask themselves "Do you think I can get one more dive out of this scrubber" not to save money, but because they don't want to go through the hassle of changing out the scrubber. My wife hates it when I bring my rebreather along on trips because I am constantly tinkering with it during surface intervals, at night, getting up early to set it up, looking for O2 fills, doing predrive checklists, etc. Then when I am underwater, I pay less attention to her, because I am constantly messing with my rebreather. I enjoy it. She says I look preoccupied.

What I am trying to say here is: Diving a rebreather will never be as easy as OC, so sometimes in our laziness, we cut corners to save time and hassle. Pushing the scrubber unfortunately is one of those corners.

I actually met a woman on a Inspiration classic gearing up at Peacock Springs Florida to do a cave dive. She was bragging that she already had 9 hours on the scrubber, and had no problem doing another quick dive. She said it was too much hassle to change it out, just for another "quickie". I thought to myself at the time, that she was another statistic waiting to happen. IMHO, the bottom line is, the longer we have the units, the more complacent we become, and we wish for the old days of simplicity with OC. OC=very little headache and preparation. CCR=constant diligence, lots of extra time, paitence and money. It will never be as simple as OC, and as such should not be used except by people who are analy retentive!

Sorry, got to run now. I need to grease my Orings, change out my sensors, change my scrubber, replace my batteries, find some O2, set up my Vision software properly, perform a predive check on all systems, remain completely diligent and focused during the dive, and get home in time to do a thorough cleaning of the entire unit and reorder some scrub and O2 for tomorrow's dive. Sounds nice and relaxing doesn't it! Now why do I dive these dang things?

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gtzavelas

do you have the link for this???