Can CCR's be safe?

[Ben M]

No, you missed my point or I didn't state it clearly. I was saying that the OC divers get blown out of the cave pretty quick and the CCR divers have a similar elevated exertion for a much longer period of time because they don't have the same gas limits. At JB in at today's flow rate, it's rare to run across OC swimmers much past the 2nd T, but I'll see CCR swimmers easily twice that far.

[matt_w]

if you are correct they should be having heart attacks on OC more often than CCR, the stats presented at RF3

You have said this a few time but the data does not show this. The OC data in the RF3 findings does not list any health problems, but the 2012-2015 DAN report list health problems as the trigger in 15% of fatal accidents and cardiovascular disease being the second leading cause of death at 15%. The RF3 report puts MI at 8% and no other direct health problems. I realize now why you haven't shown anyone where it appears in the findings. No one is saying that rebreathers don't have a higher fatality rate than OC scuba (recreational or technical).

The data may come from slightly different time periods, but it is good enough for are purposes.
There is not a higher rate of fatalities related to medical issues for rebreather divers and it is really not helpful to a discussion of rebreather safety to suggest this is true. If you have actual data from RF3 that shows something different I would be happy to proved wrong. It is a long document and perhaps I missed something.

There is nothing wrong with pointing out the importance of health and fitness for rebreather divers. These are in fact important for all divers. We should not lose site of the fact that skills and complacency are what are killing rebreather divers. I only have about 90 hours on my rebreather and I know I am still a newbie. My biggest fear is believing I am not.

[DA Aquamaster]

That's a good point Ben, we're certainly swimming more in Ginnie than we have in the past.

However there are other factors that might come into play.

For example, I don't think we're working any harder on CCR than we did on OC, and in fact I think we're going slower and working less as we're satisfied with a longer bottom time, given the more efficient deco and the reduced gas consumption.

On OC if you're adhering to a dive plan and gas plan, time, speed, and distance covered matter more than they do on CCR, where you've got more time for any given amount of deco you want to limit yourself to (at the turn or at the end of the dive) and where you don't have the finite gas limits you have on OC.

Plus, if you're doing stage dives on OC, you're hauling those stages on each and every dive, which is a lot of work if you're swimming them. In contrast, if you're on CCR and you're doing several dives in a system, you can just drop bailout gas every thousand feet on the first day and just leave it there until you're done diving the system on that trip. You just haul it in and out once.

One of the reasons we went to CCR was to reduce the work load on longer dives.

[Jont]

There's no question that an increase in WOB taxes the respiratory system, there's no question that given the right circumstance, underlying medical conditions can be triggered as a result of the additional stresses on the body. The most obvious is a heart attack. Heart Attacks are common, most survive on land but underwater the odds are LOW.....

diving = risk
RB diving = more risk
deep diving = more risk +
deep diving on a rebreather in a cave = risk ++++++++

Divers need to determine the risk tolerance level they find acceptable. Responsible divers will take a comprehensive look at the life they live considering their families, financial obligations, etc. in order to establish that threshold.

In a free society you absolutely have the right to make choices that could lead to your death, you do not have the right to make everyone around you pay for those choices should you die.

Unfortunately the weakest link with these high risk activities is training and thats a direct result of the "price point shopping" mentality, sooner or later quality suffers.

Cheers,

JonT

[Kelly Jessop]

. The most obvious is a heart attack. Heart Attacks are common, most survive on land but underwater the odds are LOW.....

Underwater compared to out of water is probably not the survivability factor you want to look at versus age. Most cave divers get out of the sport at very advanced ages, and this group can survive myocardial infarcts more due to collateral circulation. The demographic age that supports cave diving, if the upper median level has a myocardial infarction,they will probably not survive,but of course lower probability underwater due to delays on getting urgent attention.

[Seya]

yeah, get the findings from RF3. I attended

Thanks

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[Garth]

I have been doing a bit of research into getting an eCCR and training soon but with all of the deaths that have been going on lately and the likes of Wes Skiles (among other equally experienced divers) winding up dead while on rebreathers, I have been rethinking this.

My questions are what needs to be done beyond certification to ensure that a CCR dive is safe? Are there flaws with the typical unit? What additional safety equipment is necessary to make them safe? What additional protocols should be practiced to prevent mishaps? Are current training standards adequate or with every unit having its own course is there too much leeway?

You would have enjoyed the functional safety of CCRs discussion at TekDiveUSA.

The themes I took away that seem to answer your question is that training standards are improving and most manufacturers are encouraging that.

Also, diver mindset, awareness and adherence to the actual checklists and predive preparation seem to be the most important.

And lastly, diving a rebreather has its own "first rule" where in recreational scuba it is to "never hold your breath", in rebreathers it's "don't be cheap." This was reinforced by the discussion of changing cells (some people push the limits there) as well as sorb, and other consumables, o rings, and other ####.

Basically, to be safe don't be a dick and think you know better than the people who make the rebreathers.

Garth

[floridabob]

And lastly, diving a rebreather has its own "first rule" where in recreational scuba it is to "never hold your breath", in rebreathers it's "don't be cheap." This was reinforced by the discussion of changing cells (some people push the limits there) as well as sorb, and other consumables, o rings, and other ####.

Basically, to be safe don't be a dick and think you know better than the people who make the rebreathers.

Garth

Interesting thought since the makers of rebreathers don't make any of those consumables.

Not disagreeing just find it a curious logic loop.

Bob

[Jont]

Interesting thought since the makers of rebreathers don't make any of those consumables.

Not disagreeing just find it a curious logic loop.

Bob

LOL.......LOL

Leave it to you to point that out Bob...........for the love of God Bob............

[Garth]

I think the discussion was spot on regardless of whether they build cells or not. I think us divers can get caught up in i know how to do this better so I make the rules and this can get us into trouble.

I don't claim to be the most experienced diver at all so I simply was trying to take the information I heard at the conference and apply it to the original question. It would probably be better if another person who was there could recount what they heard too.

Garth


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