Are SCR's the RHSC of the Rebreather World?

[Gill Envy]

Thanks for the responses. I have poked around on both this site and rebreather world, however, since I am more "Known" here, I figured I would not be seen as trolling with my question. It seems most you guys cross pollinate over onto that board. I am definatly going to go into a rebreather, right now I am weighing the pro's and con's of a eCCR and a mCCR. But I think ultimately its going to come down to infrastructure and local area support.

you are ridiculously close to the Meg hatchery you know, even closer than i am here in seattle, I believe. I highly recommend you check out the copis meg. it's very rogust, can take the shore diving we do here in the north west. You have many options as to configuration (in fact that is so true that I couldn't make up my mind and originally bought an evolution instead). The copis is a nice platform. you can choose to go eCCR down the line if you want by "upgrading" to the shearwater controller or getting an eCCR head or adding the hammerhead. here is what i've done so far with mine:Installation of the Shearwater GF and HUD to the Copis Megalodon Rebreather - a photoset on Flickr . It might look ominous but it's really not that big a deal. with this set up I've got redundancy in po2 monitors and even a whole extra handset to plug in if things go south on a remote trip (which is where they usually go south!).

The risk debate aside, the number one reason for choosing an mCCR is reliability. your chances of finding an in field solution to a problem and not loosing dives or whole dive trips are much reduced on a manual system.

good luck in your choice! feel free to look me up if you come north some time.

george

 

[Mr.X]

In the final analysis of nearly every rebreather accident it is found that the fatalities are happening on eCCR's , nearly exclusively.

deaths on mCCR's=1
deaths on eCCR's= 150 ish

Despite increasing popularity of mCCR's, this ratio does not seem to be budging one bit.

But, I'd have to agree it's not that eCCR's kill, it's way more likely explained by the dramatic difference in monitoring interval that is absolutely required by an mCCR from day one in the swimming pool. throughout a dive an mCCR diver is doing little miny diluent flushes, O2 flushes, validating the sensors and getting to know the o2 injection requirements of each aspect of the dive profile. It's sounds sketchier to those who have not given it much time but I call it the school of predictable livable consequences vs the school of unpredictable deadly consequences. the monitoring interval required by an mCCR increases the likelihood that a malfunction or mistake will get caught before the gas mix goes deadly.

From day one, an eCCR diver is left guessing weather their monitoring interval is adequate... it's a crap shoot with little positive reinforcement.

After having dove both for a decent number of hours, there is no question in my mind why more people are making fatal mistakes on eCCR's.

I just wish that folks that went on about the dangers of rebreathers and their high risk track record would get their numbers straight and make a distinction between eCCR's and mCCR's when they are making such gross generalizations.

It looks to me so far like mCCR's are, as a system of diver and kit, leading to lower mortality than OC and I think credit should be given where credit is due.

g

Is there a link to the MCCR fatality? Very curious to know the events leading to a fatality. I also haven't kept up on the RB statistics from the ever-contentious Rebreatherworld. Thanks.

X

 

[caveseeker7]

Am not quite sure, maybe the guy using the gorilla valve ... would have to check the ever-contentious Rebreatherworld ...

 

[Mr.X]

Am not quite sure, maybe the guy using the gorilla valve ... would have to check the ever-contentious Rebreatherworld ...

LOL! Cheers.

X

 

[wedivebc]

From day one, an eCCR diver is left guessing weather their monitoring interval is adequate... it's a crap shoot with little positive reinforcement.

After having dove both for a decent number of hours, there is no question in my mind why more people are making fatal mistakes on eCCR's.

I just wish that folks that went on about the dangers of rebreathers and their high risk track record would get their numbers straight and make a distinction between eCCR's and mCCR's when they are making such gross generalizations.

It looks to me so far like mCCR's are, as a system of diver and kit, leading to lower mortality than OC and I think credit should be given where credit is due.

g

Can you point me to some hard data that indicates diver death caused by a failure of a rebreather? I know there are a couple of rather definate ones but you have to agree a vast majority of CCR failures were the result of the divers themselves, either in the pre-dive or properly responding to dangerous conditions. The safety issue between eCCR and mCCR has more to do with the mindset of the user than equipment itself.

 

[caveseeker7]

Is there a link to the MCCR fatality?

Not much known other than that it happened. Very experienced diver by the name of Jackie Smith testing new equipment for and with a friend.

Newspaper report's gone, then again they usually ain't worth the paper they're printed on (explains why post them on the web these days). Some quotes on at scuba geek's, 3rd or 4th down.

A thread at RBW, some comments by Charles Johnson, his friend, but not much info either.

Not that any of this has much to do with the Dolphin the OP asked about ...
we oughta get back on track.

 

[Mr.X]

Not much known other than that it happened. Very experienced diver by the name of Jackie Smith testing new equipment for and with a friend.

Newspaper report's gone, then again they usually ain't worth the paper they're printed on (explains why post them on the web these days). Some quotes on at scuba geek's, 3rd or 4th down.

A thread at RBW, some comments by Charles Johnson, his friend, but not much info either.

Not that any of this has much to do with the Dolphin the OP asked about ...
we oughta get back on track.

Thanks for the links! I appreciate it. I do remember the Gorilla valve.

The ECCR/MCCR/SCR propensity towards accidents, or fatalities is best left to the hard-slinging pundits of RB world...they can +, or - blob each other as much as they want there. In the end, it becomes a somewhat circular argument.

As the original discussion was about types of rebreathers...it comes without saying that researching, choosing, training and being constantly vigilant are all components of a being "safer" rebreather diver.

 

[Windwalker]

Thanks for all the great information gentlemen. Definitely a lot to chew on. From what I have discovered with the eCCR and mCCR debate related to deaths has mainly been due to Diver error coupled with lack of diligence or equipment failure. I am noticing a trend more towards safety with the increased training for both eCCR's and mCCR's, and the inclusion of superior monitoring devices like redundant monitoring systems and HUD's. As with flying airplanes, 80% of crashes are pilot error. I am getting the feeling that diver deaths on rebreathers has a very similar statistic. I figure if I kill myself, it was because I took an unnecessary chance and lost the gamble. Thank you Caveseeker7, your very detailed feedback was incredibly helpful, and I appreciate you taking the time in being so thorough.

 

[WD8CDH]

In the final analysis of nearly every rebreather accident it is found that the fatalities are happening on eCCR's , nearly exclusively.

deaths on mCCR's=1
deaths on eCCR's= 150 ish

Despite increasing popularity of mCCR's, this ratio does not seem to be budging one bit.

But, I'd have to agree it's not that eCCR's kill, it's way more likely explained by the dramatic difference in monitoring interval that is absolutely required by an mCCR from day one in the swimming pool. throughout a dive an mCCR diver is doing little miny diluent flushes, O2 flushes, validating the sensors and getting to know the o2 injection requirements of each aspect of the dive profile. It's sounds sketchier to those who have not given it much time but I call it the school of predictable livable consequences vs the school of unpredictable deadly consequences. the monitoring interval required by an mCCR increases the likelihood that a malfunction or mistake will get caught before the gas mix goes deadly.

From day one, an eCCR diver is left guessing weather their monitoring interval is adequate... it's a crap shoot with little positive reinforcement.

After having dove both for a decent number of hours, there is no question in my mind why more people are making fatal mistakes on eCCR's.

I just wish that folks that went on about the dangers of rebreathers and their high risk track record would get their numbers straight and make a distinction between eCCR's and mCCR's when they are making such gross generalizations.

It looks to me so far like mCCR's are, as a system of diver and kit, leading to lower mortality than OC and I think credit should be given where credit is due.

g

George,

I agree compleatly. It's more the diver and his monitoring than the equipment style. In fact, I think it is the particular equipment design rather than if it is eCCR, mCCR or SCR as far as equipment goes. I have seen and dived poor and good examples of all catigories of rebreathers (including a prototype artificial gill rebreather ) and my take on the safety of each has centered around the human interface more than any other factor. In general, I prefer mCCR with constant mass flow addition or a passive SCR like the RB-80, both with redundant O2 display.

 

[caveseeker7]

Thanks for the kind replies.

The way I look at it, all rebreathers have some faults, some weak points.
Some more, some less, all can be managed. None of them we should have to, as a lot of it is just lousy engineering and refusal of the manufacturers to fix the problem. More often than not they just blame the user. Sometimes they right, sometimes not.

I'm sure that'll change eventually when bigger companies with more engineering bucks and higher financial stakes join the race. Some of the current, smaller companies will vanish, some will be gobbled up and some will get their stuff straightened out and continue to sell RBs. The Poseidon/Cis-Lunar and Hollis/Steam Machines deals are imho indicators of this trend.

Looking at accident data that's available, there are so many little, stupid, unnecessary mistakes that have cost lives, or compiled to do so, something will have to change. But the debate about what caused accidents, what could have prevented it or can in the future, is endless. The training, the units, simply us humans failing, all or none of it. Arguing it usually accomplishes little and ends up in miserable disputes no one needs or benefits from.

Best thing one can do for the time being is either wait a bit and see how it develops, or very seriously and honestly analyze oneself, the dives, the units available and how they match the wants and needs. For one person that will be a SC unit, for another a CC one. And some people may realize that they're not for RB diving, and RBs are not for them. Nothing wrong with that, either.