Rebreather Safety

rebreather_jon

Hi Everyone

I have a question:

I read that there have been seven to eight deaths on the Megalodon on one thread and that there are roughly 600 Megalodons out there on another thread. Does this mean the death rate of Megalodon users is roughly 1%? Can anyone confirm these numbers?

What about Inspiration? There are so many units out there, the death rate can't be 1%? Or can it? To me this number seems to high. Especially if you consider that most people have used their rebreather for less than five years.

How much can be attibuted to human error (insufficient training, not diving with a buddy, neglecting warning signs, improper maintenance)? Why is it that we see pros (i.e. Waynne Fowler) die on these units?

I know this is a difficult subject. However, we have to keep ourselves safe. Anyone?


Sincerley,

Jon

jradomski

not even close.. I was at the factory in late March and units shipped were in the 280s (don't remember the exact number).. As far as I know there have only been 7 deaths on the meg..

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DaveC

ONLY??? Isn't that making light of a serious number? With 280 units sold, that 7 is more then 2%. And seeing how Megs haven't been around for all that long, that number is scary.

Stephane

Hello Dave,

Are you sure that all these deaths were caused by the machine and not by anything else?

Gill Envy

jon, it seems that your question is both about rebreathers in general and also more specifically a comparison about the safety of the megaladon vs the inspiration. As a new rebreather diver (I apologize in advance if I come across as blindly faithful and over zealous), this is an area i have focused a great deal of energy on in choosing which unit to go with, though I am by no means an authority on the subject and in the end had to go with my gut. I have heard from a friend who has connection with inner space that there are about 300 megs out there, it sound like 280 is a more exact number. If my understanding is correct the inspo totals in the thousands and the evolution totals around 500 units. Trying to compare the safety of each based on the number of fatalities on each model is not necessarily a very good gage, but a natural thing to do none the less. I think it’s the pros that take the hits because they are the ones at the cutting edge of what has been done, they are the pioneers pushing the envelope. History is full of the discoveries of pioneers as well as their perilous and sometimes fatal adventures. I have to say that when we dropped in for a meeting at my old dive club here in seattle to get up to speed on the latest with re-breathers and they were holding a memorial for Zack, who died on a meg, (he used to give me air fills, at my dive shop!) it did not bode well for rebreathers in general or the meg in particular with my wife and I…it was only natural to take it as an omen of some sort. But I resisted this and in the end it was not enough on it’s own to steer me away from the meg. I think the number of increased fatalities on the meg likely has more to do with it’s rise in popularity with pretty hard core pioneering divers. It’s very hard to know in the end and this is a topic of much debate on this board that seems to boil down to speculation and opinion. I’m frustrated by the lack of solid evidence as to the actual causes of death, it makes me wonder if we are not all missing something that is staring us in the face. I have promised myself that with each death I will re-confirm my resolve to stay disciplined and stay on my toes with what I’ve been trained to observe and also to take another look to see if there is anything that I can do to improve my safety, in particular anything I can learn from the mistakes of others.
Without solid evidence about which unit is actually less likely to kill me under the conditions that I dive, I was won over by a few redundancies and safety mechanisms of the vision electronics on my evolution. Here is my case for why I think the vision electronics is the most reliable. (Keep in mind thought that I only have about 700 minutes on my rig and am just sharing my opinion, not trying to invalidate anyones different choice)
Unlike many meg divers who fly their rigs manually, I am of a different philosophy and like the idea of “auto pilot flying” unless conditions require otherwise and am thus very happy with the vision electronics. I think it's best to either go with a unit like the KISS that is completely manual, requiring constant monitoring or go with the model that has the most redundant automated system...and still pay constant attention to what it is doing.
The vision’s continuous injection system, built in deco, temp stick, redundant real time dual PO2 controlling systems, independent yet combinable battery systems and the sheer volume of vision electronics out there with very few deaths (only 2 that I know of) all convinced me that the vision electronics were the way to go as far as safety and convenience and yet I know that nothing can replace good common sense and staying alert.
The continuous injection system of the vision electronics is designed to inject oxygen continuously if the PO2 drops suddenly for any reason until the set point is regained not injecting just at set intervals. This system has the ability to respond rapidly, and it makes for a good argument that my chances of passing out from a sudden drop is less likely.
The temp stick, while not perfect is a major advancement in my opinion. Aside from likely preventing you from getting very far if you forgot to change out your scrubber, it gives a “real time” gage of how reactive your scrubber is. I think it’s fair to say it reduces risk of exhausting your scrubber, but again, no empirical stats to back it up and there are some conceivable scenarios where breakthrough could be possible even if the gage showed it were functioning normally.
We are confident that the trimix version (other versions have been buggy in the past) of the vision electronics makes either the evo or inspo the most reliable rebreather on the market today, at least for the kind of diving we do. And so far it SEEMS that it’s track record of low deaths supports this. I hope that helps. Safe diving, whichever model you choose!

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Gill Envy

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Mark Chase

Having looked at a few options I tend to agree with the above. The Vision seems to offer the best of the two units in terms of pure safety features. I am not convinced with the fussy display on the Megs HUD and I am even less convinced about the calibration process on a meg. The Vision would appear to offer more and the temp stick is better than nothing as a scrubber monitor.

That said all CCR's are dangerous.

I like the meg a lot, if i had unlimited funds i would get a Boris for the UK and a Meg to travel with but the number of hits on the unit in the last two years is alarming. It is a big problem when accident investigation on CCRs is so limited and inconclusive.

ATB

MArk Chase

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jradomski

No I wasn't making light of the number, but 7 is better than 8..

Still 1 is too many..

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Joe Radomski
CCR Trimix Instructor Trainer
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All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.

decoweenie

I have been diving Rebreather only since 1998 and have read most, if not all, of the accident reports available to me.

And I can't recall a single conclusion from these reports that the unit was at fault.

The only one came closest (IMHO) was the failed mushroom valve on an earlier version of a Rebreather-80-clone unit (which is now rectified). However, the owner did supposedly contribute to the problem by "boiling" the mushroom valve to disinfect it.

So my point is... If anyone looking for solid "proofs" that any unit was responsible for causing these fatalities, or just more prone to have problems which could lead to the fatalities, best of luck to you since I have not seen/heard of any.

But does it mean that they don't exist ? Huhmmm...

Personally, I stay away from units with high accident rates and nobody seems to be interested in investigating the possible cause...

Andy M

I think this is an important point and worthy of further discussion. While the percentage attributed to the Meg seems high, this rebreather is often associated with long, deep tech dives and so, would reasonably have a higher death rate than some other rebreathers. I think a sample of 7 out of 280 is fairly statistically valid.

Nevertheless a 2% death rate is somewhat higher than what the public at large would accept. Would you drive a car that had a 2% death rate? a plane? The quality of training on the meg is, probably fair to say, better than any other rebreather as the group of meg instructors is still fairly exclusive.

Ok. rebreather diving is dangerous, but 2% makes it a ridiculously dangerous activity.

Is there too much dependence on training here to keep the user alive? Are Keep-you-alive failure mechanisms needed here for when training fails or when the user is incapacitated due to O2 convulsion etc? You can bet that is what would be expected if this death rate was observed in any other, more public sport/hobby, there would certainly be changes made!

Andy

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PeteS

Well, IMHO.....

When the first Inspirations hit the market in the UK, the masses were exposed to CCR diving. Within the first few years there were some accidents on them that resulted in the deaths of some very experienced divers. Most of these accidents were due to errors made by the divers themselves. As others have already said, I cannot recall a single cause of death being atributable to a unit (I'll stand corrected, if need be). What happened following those first few years was that diver training and awareness improved. There are still deaths on Inspirations (I helped pull the body of a friend out the water last september) but they seem to now be far and few between.

I can only suggest that in the past couple of years the USA has become exposed to the Inspiration, Meg, Kiss etc, and is going through the learning curve that the UK went through. However, that the learning curve is still very steep and sometimes people get hurt.

I also feel that the worldwide CCR market has expanded to include the less experienced divers. This is also a factor in higher accident rates.

Whatever you are selling or doing, there will always be people who end up, either by accident or design, outside the "comfort zone", can't do the right thing to climb out of the incident pit, and die.

As I said at the start, just my humble opinion......

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Pete S.

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