Mike Young
New Member
You just don't go where we go
mCCR myth debunked - Do you agree?
- Thread starter jkaterenchuk
- Start date
You just don't go where we go
Hi Mike,
Great to see you on here! For those of you who don't know Mike, he is the owner of KISS Rebreathers.
Regards,
Randy
I find it somewhat curious that people can get so worked up about whether mCCR or eCCR or hCCR is more or less safe than their cousins. To me the bottom line of this paper is pretty obvious: CCR in general seems to have a higher mortality rate than OC. We can argue the fine points about whether the data supports one model of rebreather over another, but I suspect that regardless of what data is shown to support one view or another, the community will still draw lines along "party affiliation". It's almost like the rednecks that argue about "Chevy vs. Ford" and who has the best pickup truck. IMHO, the CCR community will never see eye to eye on this, primarily due to the fact that all of us have paid enormous amounts of money on equipment and training. We all want to feel that we have made a wise decision about our investments.
The critical thing going forward is that we do all that we can to stay focussed on improving the quality of training, the vigilance with which we prepare for our dives and the proper maintenance of our equipment and consumables.
Just my $02.
Regards,
Randy
The critical thing going forward is that we do all that we can to stay focussed on improving the quality of training, the vigilance with which we prepare for our dives and the proper maintenance of our equipment and consumables.
Just my $02.
Regards,
Randy
Andy Del
still causing trouble!
The problem isn't with Andrew's paper, but with what people take away from it. This entire thread is based on the STUPID assumption that there is some sort of eternal truth being revealed. There is not.
Research and publishing is not intended to be the final say so on a subject, but a revelation of effort and discovery. The most common finding in the papers I read is that more investigation is needed. Following that, new avenues are indicated for investigation.
There is no myth, there is no debunking.
To think otherwise is foolish. To think that there is a simple answer is likewise foolish. To limit one's mindset to training, preparation and maintenance is likewise blinding ones' self and going down the path of becoming a statistic.
cheers
Andrew
Research and publishing is not intended to be the final say so on a subject, but a revelation of effort and discovery. The most common finding in the papers I read is that more investigation is needed. Following that, new avenues are indicated for investigation.
There is no myth, there is no debunking.
To think otherwise is foolish. To think that there is a simple answer is likewise foolish. To limit one's mindset to training, preparation and maintenance is likewise blinding ones' self and going down the path of becoming a statistic.
cheers
Andrew
Andrew,
Not quite sure how how you read into my statement that there was a "simple" answer to any of this. I would only hope that we can all agree upon the fact that these 3 items are things that we as educators and divers have some amount of control over. Will they solve every problem? Not really, but they are surely a step in the right direction.
Kind regards,
Randy
Michael Thornton
Rebreather Enthusiast
I don't think he was talking so narrow mindedly as you may think. It is similar to what you said elsewhere
By training I would include not just your course with an instructor but your continuing education via good buddies, learning from others on forums and anything that can make you more aware, better equipped to properly plan and execute a dive safely and successfully.
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Michael Thornton
Rebreather Enthusiast
Would it still be if there were more people still doing big OC dives?
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Good question!
Mark Chase
ATB=AlwaysTalkingBollocks
JP dives mainly on the south coast of the UK which is where APD is bassed so hardly surprising there are predominantly APD units around.
Lot of UK KISS owners in Scotland it seems
So Mike can you confirm my theory that we have 500 odd Classic Kiss units sold since 1999?
And why are manufacturors so concerned with letting us know how many units have been sold?
ATB
Mark
Simon Mitchell
Well-Known Member
Mark,
With all due respect, and as someone who agrees with 99% of your posts on the internet, you speak as though you have done the research, which you have not. Dr Fock has done the research, and his conclusions are not the same as yours.
Predictably this paper has pushed a lot of buttons. It is not surprising that those with long held personal beliefs that are challenged by this paper do not like it. On the other hand, those whose beliefs are confluent with the paper's findings will agree with it. What we all need to understand is that this is the only proper attempt to apply even vaguely credible methodology to a problem that has not hitherto been addressed. In particular, it is the first published study to address these questions about the risk of rebreather diving using sources other than the experience of our own personal worlds and dive groups, unit preferences, impressions driven by internet posts, and other heavily biased sources of information. No-one, including the author, is pretending that it is perfect. But whether we like it or not it is the best there is at the current time.
This is not my work, and I do not intend to get into protracted debates in its defence. However, there are a couple of points I would make based on some of the comments so far.
First, READ the paper. Some of the questions people are asking are addressed in there.
Second, the data are not derived from the Deeplife database as such. That database was used as a starting point, but its duplications were removed, numerous known mistakes were corrected, and new data on many accidents was sourced. The interpretations of causation in the original deeplife database were virtually ignored (because many of them were agenda-driven rubbish), and causation was reinterpreted where the information available allowed an interpretation.
Third, the observations about safety of mCCR vs eCCR arose from comparing an estimate of the relative proportion of mCCRs and eCCRs use among rebreather divers with the proportions of those respective types in the fatality data. The estimate of relative mCCRs vs eCCR use was largely derived from over 1500 members of rebreather world who had registered the type of unit they dive. Is this sample representative of the rebreather diving universe? Who knows? I can't think of any particularly good reason why it would not be. Moreover, the proportion of mCCRs in the RBW survey is virtually the same as an independent Dutch survey. Bottom line is that the proportion of divers saying they use mCCRs (in both surveys) is virtually the same as the proportion divers in the fatality data who died using mCCRs. In other words, they are not over-represented or under-represented, and there is no evidence that they are safer. This is not a sophisticated analysis, but it is the only analysis we have. As Mathieu said the only claim made in the paper is that it does not support the claims of superior safety for mCCRs that have become another widely accepted internet fact. It is not drawing any hard conclusions.
There are all sorts of directions you can take this debate like what sort of dives typically get done with the respective units; and the role of leaky valves etc. But I reiterate, the data are what they are, and whether we like it or not, it is the best data we currently have.
Fourth, comments about statistical validity are distracting, unnecessary and mostly wrong. For the most part this paper is not testing any hypotheses. There is ample data in some of the comparisons of proportions for Dr Fock to have run some simple statistical tests but he has simply refrained from doing so.
Simon M
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Mark Chase
ATB=AlwaysTalkingBollocks
Sorry if it sounds like i have gone to great lengths to investigate this, but its not totally devoid of research.
Lets be clear on my "research"
I did this a few years ago
I looked at the fatalities list and counted how many ECCR v MCCR deaths there were. I ignored pure 02 rebreathers SCR & and home builds.
I then followed the threads on approximating how many units there were out there of each type.
End result was a 1:250 -300 death per unit sold on MCCR and an average of below 1:100 deaths per unit sold ECCR
Some units were did stand out with the Meg having an incredible 1:40 deaths per unit sold based on the early figures.
Early figures for the Inspo were equally awful
Whilst a lot of early deaths could be put down to general ignorance of CCR diving due to limited experience of those in teaching CCR and lack of general information, its again worth noting that during the same period 1999 -2005 there were no deaths on the KISS which was probably in its hay day by 2005.
My personal conclusion has always been that MCCR makes us dive more aware and this promotes safe diving.
Its blatantly obvious MCCR is the more dangerous machine to dive but that very danger is keeping divers alive.
I struggle to accept that many divers have £5000 worth of CCR sitting in a shed gathering dust for over 12 months. Most will sell on to active divers.
I have also noticed a massive down turn in divers willing to go to do any deco diving these days. Its getting very hard to fill a boat with boat fees and gas even for a 40m dive coming in at around £120 per dive. 90% of the still active divers I know are on CCR because for us its only the boat fees that hurt.
IMHO CCR divers are far less inclined to long lay off from diving due to the very fact they were willing to invest several thousand pounds in dive kit in the first place.
Call this personal opinion, observation, research or just me talking crap but whilst I appreciate the effort put into the report i struggle to reconcile some of the conclusions with my own experience QED i raise the question for further debate.
I remain open minded.
ATB
Mark
Ben Field
All IMVHO obviously...
Yes, you can. If you remove the emotion you do "need" more fatalities (lots of them) and you need solid reporting on each of them before you can make analysis with good sound numbers to back them up, until then (hopefully never) its just guess work and IMO dangerous to suggest its anything other than guess work.
The myth is about safety, I've answered this point elsewhere but the fact is Dr Focks conclusion is IMVHO unfairly written as its a rebuttal rather than a conclusion on the very scant data.
Exactly, but the paper did not say that, it simply debunked the myth, rather than stating the evidence was just that MCCR and ECCR are equal- perhaps its a minor, linguistic detail but I was under the impression a published paper should be reviewed to remove any subjective comment and be unbiased.
Really? Its been rumbling around for more than a decade from 100's of sources yet its "doubtful", I'd say it has as much, if not more validity as Battery bounce and other things derided as myth
Ben Field
All IMVHO obviously...
I believe that in one instant its because people like to validate their choice, justify their expenditure (or what they teach in some cases) and secondly because it seems everyone has a natural axe to grind
Almost certainly, as you say- They are both dangerous so we're really debating nothing. (Much like both pickups are rubbish! ;-)
However- those of us interested in rebreathers (design, training and use) will always be focused on working towards a "best" position, best design, best training and best use, as such there is scope to debate the different methods.
That the "best" is only shades either way is irrelavent :spin:
I think the "myth" gets badly misquoted, "Safe" is such a all encompassing term, its not Safe to use it in this debate perhaps!
Perhaps we need a seperate thread to agree what the myth is once and for all?
Mike Young
New Member
yes to the best of my knowlage there are almost 500 classics out there. I have no idea how many sports.
Mark Chase
ATB=AlwaysTalkingBollocks
Chris Kennedy
New Member
KISS,Meg,JJ,Inspo,Pelagian,rEvo of in my case GAF.They all do the same job just in different ways.Don't respect them ,look after them and know all their foibles they will all BITE YOU. Statistics can be made to say anything.
Simon Mitchell
Well-Known Member
JONT
New Member
HAHA thats worth a lot more then just 0.02 and you are correct.
There's several things that these "studies" dont show and can't account for:
1) The evolution of training.
As training improves so should the quality of diver. In 1995 diving the Doria on Drager SCR's was just stupid but back then it made sense on paper and we just didnt know better.
2) Medical Conditions/events
A minor heart attach underwater is almost always fatal but is it fair to call that a "rebreather death"? or was it a person that had a survivable event at the worst possible time?
3) Inactivity vs. activity vs to much activity
Statistics when applied to the masses never lie, how does someone that dives 4 times per year maintain the same level of proficiency as someone that dives 300 hours per year and at what point is to much "experience" working against you? This is tough to quantify but none the less affects the fatality rate. This is the reason why I dont really support the idea of a recreational rebreather, a recreational diver, not to be confused with a professional that dives within recreational limits, can't be expected to maintain the same level of knowledge, skill and experience as a person that dives well beyond what's considered recreational. Not even the most advanced, fully automated rebreather can beat that one.
4) Unique circonstance:
Is a rebreather diver that dies as a result of being lost in a cave really a rebreather death? or is it a cave diving accident? if so why was he lost? Is a rebreather diver that dies on a unit SOLO without training and without bailout a rebreather death? or was it a jackass that died because he was two good for the most fundamental of rebreather diving rules?
The problem with all of these "studies" is that they are generated to serve a purpose thats usually duplicitous in nature, truth be told toilet paper is more functional.
Four VERY well credentialed and very experienced divers I know asked me what I thought the best course of action is since the diving they do is at the limit of OC so rebreathers at this point are the best option.
I said the following (this applies to divers that are doing 4000++++ foot penetrations in 300+ feet of water, so take it for what its worth):
"If I knew in 1995 what I know today I would have done thing very differently, I'd learn to dive a rebreather on an MCCR because the education in and of itself instills some very good habits, after 100 hours I'd add an electronics package given the task loading that comes with the dives your talking about, practice for two years then revaluate".
At the end of the day its the DIVER and the decisions we make, and what guides that? Open mindedness, knowledge, practice and experience.
Unfortunately not kit is going to ever replace the diver and the human decision making process.
Ben Field
All IMVHO obviously...
This is true but the situations we have is such the the choices of equipment a diver makes potentially have a bearing on their training, experience and eventual choices at the moment of the incident and possibly even lead to the type of fatality they may suffer!
This paper seems to me to make a negative statement about MCCR's in favour of ECCR while lots of anecdotal evidence suggests the opposite.
I have no axe to grind in either camp, it matters naught to me which type folk choose (unlike many on here who are instructors and earn a crust from pushing people towards their "choice")
If analysis of real data shows us something we should take note, Dr Fock suggests both systems are equally dangerous, I'm not sure thats a revelation but in fact something we already knew.
The "myth" isn't (IMVHO) about the lethality of the different systems but about how they are dived and how you handle issues, of that their is seemingly no data at this time.