Rebreather Safety

***jradomski*** · 26th April 2006, 08:34

Quote: (Originally Posted by 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

I would normally agree that the difficulty of a dive could skew the numbers but none of the deaths were really big dives..

one was a training dive in 18m of water, one was in 4m of water, The first one was shallow (dont know exact depth but it was less tha 18m). 3 were between 45-55m and one at 69m..

One death seems to be caused by someone who went well beyond the scrubber limits, 2 of the deaths were by experienced divers but relatively new CCR divers that I heard had a long layoff from diving the rig.. 1 was probably a medical issue..

so of the 7, 3 may be questionable..

Micko · 26th April 2006, 08:45

Hey list due to the sensitivity of this subject pls no person take any offence.
After reading the happenings in the past months i have found that I, and im sure i speak for other people have cast there memory back at some stage and recalled a time when we have all made a mistake .

Being putting our kits together.
Pre Dive check missed something.
??ing what do i need to service.
I will do it tommorow.
The sorb is fine.
Theres a small leak fix after this dive.

Look i could go on but it all boils down to we get in a routine.
And that means Complacent well this is where the shit can hit the Fan.
Im not saying its human error or units error but given the nature of our lives in this day and age we all tend to live a pretty high pace life.And this is not just about diving.

Whether rebreather A has more accidents Rebreather B i dont think this is our key focus point.
It should be ourselfs take our time and think everything out.
It is proven regardless of exp these machines will KILL.
Give them the respect they deserve.

Ignore spelling I suck at it.... {and i dont care}
Be safe guys

John Bantin · 26th April 2006, 09:48

Rebreathers are dangerous.
Diving is dangerous.
In my time I have owned some very high-performance motor cars. I was always a little scared of them. When I drove fast I knew that my life was on the line. I rarely used them to their full potential.
I am scared to death of rebreathers.
I have taken some flack for my alpinist views on using rebreathers but if I was not one hundred percent sure that the rebreather I was about to use was in perfect operating condition, I would not use it.
I have made lots of mistakes using a rebreather. I am not afraid to tell anyone about them. I have been able to 'manage' the mistakes through judgement and possibly some luck.
I always approach rebreather diving from the point-of-view that if my unit is not one hundred percent OK, it will kill me. I systematically check it.
I once went all the way to Rangiroa only to find I could not get a successful neg pressure test - so did not use that unit even though the leak was miniscule. My cowardice has kept me alive.
Be a coward. The brave die young.

Tim Cashman · 26th April 2006, 09:55

I think Rebreather accidents are primarily caused by complacent or distracted divers. Full time 100% awareness of what your marine gas blending unit is doing, is essential.
I did hear a rumour that CO2 could bypass the meg scrubber through the water drain though, but this fault has been modified? Anyone know something about this?
Tim

**nigelh** · 26th April 2006, 09:55

Quote: (Originally Posted by Micko)

It is proven regardless of exp these machines will KILL.
Give them the respect they deserve.

I guess when you come down to it the most dangerous thing is seeing the statistics and saying "Well my unit is safer than his so I can slack off on all these boring checks".

I take my rebreather places I never went on OC so I must be more at risk. For some things it's safer but there are more subtle problems. OC is nice and clear cut - you can breathe or you can't. We all know that it isn't that simple for us.

decoweenie · 26th April 2006, 10:00

Quote: (Originally Posted by nigelh)

I guess when you come down to it the most dangerous thing is seeing the statistics and saying "Well my unit is safer than his so I can slack off on all these boring checks".

I don't think anyone has said that.

And I agree that it would be the wrong thing to do/think.

Mdemon · 26th April 2006, 10:00

There were more than a few deaths when the Inspo/"WidowMaker"/ "Yellow Box of Death"/"DeathBox" came out. But, I guess as the training improved and lessons were learnt, that rate has reduced.

The Meg is new and the owners and trainers are still learning. If there is no inherent flaw then I would assume the mortality rate will also slow for this unit.

decoweenie · 26th April 2006, 10:08

Quote: (Originally Posted by Mdemon)

The Meg is new and the owners and trainers are still learning. If there is no inherent flaw then I would assume the mortality rate will also slow for this unit.

Do you really believe this holds true in general ?

(Knock on wood as I type this)

The CK has the same number of units as the Meg, and the SK is catching both. No fatal accidents on either unit.

(still knocking on wood)

I know that Tom and Mark took their Megs very deep, but in general, I don't think the average Meg divers dive much deeper than the average CK divers. So I don't necessary agree that the fatality rate on the Meg is proportional the supposedly high risk dives.

Also looking across the forums, I see that majority of the Meg divers are first time Rebreather owners similar to the CK, so again not agree that the average experience level is higher.

But I sincerely hope that you are right about the mortality rate will slow down...

Mdemon · 26th April 2006, 11:51

Based on nothing more than intuition, yes.

The Meg is a more sophisticated piece of kit than CK. There are differences between a Meg and other RBs in general. Those two factors combined may mean that (if there is no inherent design flaw) there are better ways of doing things on a Meg which may be discovered in time.

So, if calibration (for example) needs a new procedure to make it safer then when someone comes up with it, the benefit will be spread amongst the users and using a Meg would (in this hypothetical example) be safer.

A pet theory, nothing more...

Padowan · 26th April 2006, 12:22

This statement:

Quote: (Originally Posted by decoweenie)

<snip>
The CK has the same number of units as the Meg, and the SK is catching both. No fatal accidents on either unit.<snip>

Is totally supported by this one:

Quote: (Originally Posted by Tim Cashman)

I think Rebreather accidents are primarily caused by complacent or distracted divers. Full time 100% awareness of what your marine gas blending unit is doing, is essential.

The whole operational principle behind the KISS is that the user MUST remain more aware of the condition of the loop gas operation of the unit, than an eCCR diver.

This does make me think that a KISS principle unit with an (independant) electronic parachute is (operationally) probably the best of both worlds. But then again, the parachute may make people complacent - it's the same as the story of seatbelts - if you don't wear one, you'd probably drive a lot more carefully....

26th April 2006, 08:34	#11 (permalink)
*jradomski* Moderator Current Rebreather/s: Inspiration Classic Sport Kiss Optima rEvo Other CCR Home Build Other Rebreather/s: Inspiration Vision Evolution Megalodon Classic Kiss rEvo Other CCR Home Build Join Date: Mar 2005 Location: "Da" Bronx Posts: 2,900	Re: Rebreather Safety: Megalodon vs. Inspiration Quote: (Originally Posted by 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 I would normally agree that the difficulty of a dive could skew the numbers but none of the deaths were really big dives.. one was a training dive in 18m of water, one was in 4m of water, The first one was shallow (dont know exact depth but it was less tha 18m). 3 were between 45-55m and one at 69m.. One death seems to be caused by someone who went well beyond the scrubber limits, 2 of the deaths were by experienced divers but relatively new CCR divers that I heard had a long layoff from diving the rig.. 1 was probably a medical issue.. so of the 7, 3 may be questionable.. __________________ Joe Radomski CCR Trimix Instructor Trainer ANDI Instructor Trainer Director #10 All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated. Last edited by jradomski : 26th April 2006 at 08:40.
(Online)

26th April 2006, 08:45	#12 (permalink)
Micko Custom Title Allowed! Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Dec 2005 Location: perth Posts: 114	Re: Rebreather Safety: Megalodon vs. Inspiration Hey list due to the sensitivity of this subject pls no person take any offence. After reading the happenings in the past months i have found that I, and im sure i speak for other people have cast there memory back at some stage and recalled a time when we have all made a mistake . Being putting our kits together. Pre Dive check missed something. ??ing what do i need to service. I will do it tommorow. The sorb is fine. Theres a small leak fix after this dive. Look i could go on but it all boils down to we get in a routine. And that means Complacent well this is where the shit can hit the Fan. Im not saying its human error or units error but given the nature of our lives in this day and age we all tend to live a pretty high pace life.And this is not just about diving. Whether rebreather A has more accidents Rebreather B i dont think this is our key focus point. It should be ourselfs take our time and think everything out. It is proven regardless of exp these machines will KILL. Give them the respect they deserve. Ignore spelling I suck at it.... {and i dont care} Be safe guys
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26th April 2006, 09:48	#13 (permalink)
John Bantin New Member Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Feb 2006 Location: Twickenham Posts: 22	Re: Rebreather Safety: Megalodon vs. Inspiration Rebreathers are dangerous. Diving is dangerous. In my time I have owned some very high-performance motor cars. I was always a little scared of them. When I drove fast I knew that my life was on the line. I rarely used them to their full potential. I am scared to death of rebreathers. I have taken some flack for my alpinist views on using rebreathers but if I was not one hundred percent sure that the rebreather I was about to use was in perfect operating condition, I would not use it. I have made lots of mistakes using a rebreather. I am not afraid to tell anyone about them. I have been able to 'manage' the mistakes through judgement and possibly some luck. I always approach rebreather diving from the point-of-view that if my unit is not one hundred percent OK, it will kill me. I systematically check it. I once went all the way to Rangiroa only to find I could not get a successful neg pressure test - so did not use that unit even though the leak was miniscule. My cowardice has kept me alive. Be a coward. The brave die young.
(Offline)

26th April 2006, 09:55	#14 (permalink)
Tim Cashman New Member Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Aug 2005 Location: Wales Posts: 55	Re: Rebreather Safety: Megalodon vs. Inspiration I think Rebreather accidents are primarily caused by complacent or distracted divers. Full time 100% awareness of what your marine gas blending unit is doing, is essential. I did hear a rumour that CO2 could bypass the meg scrubber through the water drain though, but this fault has been modified? Anyone know something about this? Tim __________________ Iechyd da
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26th April 2006, 09:55	#15 (permalink)
nigelh New Member Current Rebreather/s: Inspiration Vision Other CCR Other Rebreather/s: Inspiration Classic Other CCR Join Date: Mar 2005 Location: Brighton, Sussex, UK Posts: 825	Re: Rebreather Safety: Megalodon vs. Inspiration Quote: (Originally Posted by Micko) It is proven regardless of exp these machines will KILL. Give them the respect they deserve. I guess when you come down to it the most dangerous thing is seeing the statistics and saying "Well my unit is safer than his so I can slack off on all these boring checks". I take my rebreather places I never went on OC so I must be more at risk. For some things it's safer but there are more subtle problems. OC is nice and clear cut - you can breathe or you can't. We all know that it isn't that simple for us. __________________ nigelh
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26th April 2006, 10:00	#16 (permalink)
decoweenie Crash Test Dummy Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Feb 2005 Location: Cairo Posts: 5,510	Re: Rebreather Safety: Megalodon vs. Inspiration Quote: (Originally Posted by nigelh) I guess when you come down to it the most dangerous thing is seeing the statistics and saying "Well my unit is safer than his so I can slack off on all these boring checks". I don't think anyone has said that. And I agree that it would be the wrong thing to do/think.
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26th April 2006, 10:00	#17 (permalink)
Mdemon SiegeEngine II Current Rebreather/s: Inspiration Classic Home Build Other Rebreather/s: Inspiration Classic Home Build Join Date: Feb 2007 Location: SWUK Posts: 1,906	Re: Rebreather Safety: Megalodon vs. Inspiration There were more than a few deaths when the Inspo/"WidowMaker"/ "Yellow Box of Death"/"DeathBox" came out. But, I guess as the training improved and lessons were learnt, that rate has reduced. The Meg is new and the owners and trainers are still learning. If there is no inherent flaw then I would assume the mortality rate will also slow for this unit. __________________ www.southwestmafia.com "Once the agenda-monkeys and perfect-worlders have moved on, perhaps we can do some diving?"
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26th April 2006, 10:08	#18 (permalink)
decoweenie Crash Test Dummy Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Feb 2005 Location: Cairo Posts: 5,510	Re: Rebreather Safety: Megalodon vs. Inspiration Quote: (Originally Posted by Mdemon) The Meg is new and the owners and trainers are still learning. If there is no inherent flaw then I would assume the mortality rate will also slow for this unit. Do you really believe this holds true in general ? (Knock on wood as I type this) The CK has the same number of units as the Meg, and the SK is catching both. No fatal accidents on either unit. (still knocking on wood) I know that Tom and Mark took their Megs very deep, but in general, I don't think the average Meg divers dive much deeper than the average CK divers. So I don't necessary agree that the fatality rate on the Meg is proportional the supposedly high risk dives. Also looking across the forums, I see that majority of the Meg divers are first time Rebreather owners similar to the CK, so again not agree that the average experience level is higher. But I sincerely hope that you are right about the mortality rate will slow down...
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26th April 2006, 11:51	#19 (permalink)
Mdemon SiegeEngine II Current Rebreather/s: Inspiration Classic Home Build Other Rebreather/s: Inspiration Classic Home Build Join Date: Feb 2007 Location: SWUK Posts: 1,906	Re: Rebreather Safety: Megalodon vs. Inspiration Based on nothing more than intuition, yes. The Meg is a more sophisticated piece of kit than CK. There are differences between a Meg and other RBs in general. Those two factors combined may mean that (if there is no inherent design flaw) there are better ways of doing things on a Meg which may be discovered in time. So, if calibration (for example) needs a new procedure to make it safer then when someone comes up with it, the benefit will be spread amongst the users and using a Meg would (in this hypothetical example) be safer. A pet theory, nothing more... __________________ www.southwestmafia.com "Once the agenda-monkeys and perfect-worlders have moved on, perhaps we can do some diving?"
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26th April 2006, 12:22	#20 (permalink)
Padowan Proper Boffin Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Feb 2005 Location: Kent, UK. Posts: 518	Re: Rebreather Safety: Megalodon vs. Inspiration This statement: Quote: (Originally Posted by decoweenie) <snip> The CK has the same number of units as the Meg, and the SK is catching both. No fatal accidents on either unit.<snip> Is totally supported by this one: Quote: (Originally Posted by Tim Cashman) I think Rebreather accidents are primarily caused by complacent or distracted divers. Full time 100% awareness of what your marine gas blending unit is doing, is essential. The whole operational principle behind the KISS is that the user MUST remain more aware of the condition of the loop gas operation of the unit, than an eCCR diver. This does make me think that a KISS principle unit with an (independant) electronic parachute is (operationally) probably the best of both worlds. But then again, the parachute may make people complacent - it's the same as the story of seatbelts - if you don't wear one, you'd probably drive a lot more carefully.... __________________ Padowan The future's bright, the future's Yellow .....for now padowan.net - Latest Video: Scapa Flow Rebreather Diving
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