'Clinically dead' rebreather diver dragged from quarry - and then revived

[doctormike]

Any of them, except for the manifold.

Granted, there are three O2 sensors as well, but they have been known to fail simultaneously with the same mode.

Are you saying that apart from a manifold failure, any other OC gear failure poses no danger to the user?

 

[Patoux01]

Are you saying that apart from a manifold failure, any other OC gear failure poses no danger to the user?

Who needs air anyway.

 

[KevinNM]

Are you saying that apart from a manifold failure, any other OC gear failure poses no danger to the user?

Well, it's usually obvious that there is a problem before you lose consciousness on OC from a gear failure. From 'I'm not getting any air from the reg" to "What is the really loud noise next to my ear?"

 

[Dan]

CC diver deaths relative to OC is about an order magnitude, according to this report: Analysis of recreational closed-circuit rebreather deaths 1998-2010. - PubMed - NCBI

 

[Patoux01]

But isn't the average closed circuit dive an order of magnitude more dangerous than that of usual open circuit? Or has that been taken into consideration?

 

[Dr Simon Mitchell]

But isn't the average closed circuit dive an order of magnitude more dangerous than that of usual open circuit? Or has that been taken into consideration?

Hello Patoux01,

This debate has raged for almost two decades now. Are rebreathers more dangerous because of the rebreathers themselves, or is it the sort of diving they are used for?!

Let me say up front that I dive rebreathers almost exclusively and have done so since the first recreational units emerged. I am very pro-rebreather. BUT, I am under no illusion that they are dangerous things, and my choice to use one is an informed risk vs benefit decision. They are just so good for the type of diving I / many of us do. Indeed, much of it I more or less could not do on open circuit (too deep, too long, too expensive on OC) and right there is an observation of high relevance to your question.

So, your question. As a scientist I don't think the answer matters. If rebreathers are what allows divers to do dives that are "an order of magnitude more dangerous than that of usual open circuit" then surely that is all part of the milieu of "rebreather diving" and any deaths that arise are therefore "rebreather diving deaths". Epidemiologically speaking, I think we would be on very shaky ground if we tried to reclassify deaths during rebreather diving as "non-rebreather diving deaths" just because there was no obvious problem with the rebreather. It would be a bit like saying wing suits are not dangerous because in most of the related deaths the wing suit itself did not fail.

As defensive about rebreathers as I feel, I do not think it is valid to attempt to mitigate the comparatively high rate of accidents in their use by saying that they get used for more complex dives.

Simon M

 

[doctormike]

Well, it's usually obvious that there is a problem before you lose consciousness on OC from a gear failure. From 'I'm not getting any air from the reg" to "What is the really loud noise next to my ear?"

I didn't say that there was no difference between OC and CCR. I certainly understand that difference. I was responding to the following:

KenGordon: "Which bit of an OC set can fail without posing a danger to the user?"
Blasto: "Any of them, except for the manifold."

I understand that it's cool to come here and point out that rebreathers are death traps, and therefore the accident analysis is unnecessary, it's obvious what the problem was.

Look, I respect the sport, and I have long before I trained on a CCR. I don't like bravado or normalization of deviance, and I regularly push back on that stuff here. But I do find it a little irritating that frequently people with little or no CCR experience make sweeping statements about rebreathers, and minimize the risks associated with OC diving. As I mentioned upthread, for some reason this doesn't happen in the context of risky OC tech or cave diving.

CCR divers understand, assume and mitigate unique risks to the best of their abilities. So do OC divers. Both of us do this more than golfers or knitting enthusiasts. Implying that OC gear is extremely safe because you know right away when it fails is at odds with the many OC deaths reported.

As far as interpreting that "order of magnitude" concept, I think that Simon put it best and I won't paraphrase him. Certainly he has more street cred in this field than just about anyone else.

 

[Patoux01]

As a scientist I don't think the answer matters. If rebreathers are what allows divers to do dives that are "an order of magnitude more dangerous than that of usual open circuit" then surely that is all part of the milieu of "rebreather diving" and any deaths that arise are therefore "rebreather diving deaths". Epidemiologically speaking, I think we would be on very shaky ground if we tried to reclassify deaths during rebreather diving as "non-rebreather diving deaths" just because there was no obvious problem with the rebreather.

I do believe that people are often using data from "do more people die (per dive) on rebreathers than on OC?" to answer "Is, for a given dive, a rebreather much more likely to have me die?". And that makes a difference imo. I'm not trying to "reclassify" deaths on rebreathers, I'm trying to get comparable data.

 

[Cowfish Aesthetic]

I'll just pop in to note that its been something like five pages since anyone touched on anything even remotely related to the accident supposedly under discussion.

 

[doctormike]

I'll just pop in to note that its been something like five pages since anyone touched on anything even remotely related to the accident supposedly under discussion.

The accident was a near fatal rebreather accident. You don't think that a discussion of rebreather fatalities is remotely related to that?

Or are we supposed to wait for the "official report" to discuss it, so we know exactly what happened?