Is it really worth the risk?

[dreamdive]

Yes! I like all the reasons you state. Especially the "gas clock" for cave. I am being trained to carry plenty of bailout, so if I have an issue, I have time to try to solve it.

Hello Tammy,

That's exactly how I feel! No need for panic! Just take a breath and work through the problem without having to worry about drowning. No need to swim quickly through a cave, but stop and "smell the roses" or admire the formations. Wait till you get to dive the caves in Mexico! If you think you enjoy cave diving now, you will be totally hooked then.

 

[HIGHwing]

Rebreathers look awesome in pictures, too. So there's that.

 

[Brad_Horn]

Do you not have confidence in your abilities as a Rb diver to perform the proper predive and assess issues you may face in the water, or is this truly just a marketing ploy?

Robert, confidence in my own abilities is irrelevant if a rebreather is designed poorly and in such a fashion that it fails standard testing, like that for CE. Thats why that DAN video link above emphasises the unmanned testing occur first to confirm removal of any design hiccups like the option of misassembly etc etc prior to manned diving. Its human nature to make mistakes: life's too short as it is. Why handicap yourself and increase your risk before you even get in the water, for no reason!

Having a functionally fail-safe rebreather to dive (ie. one that has been audited to at least the CE standard with the testing published), then you know it's a platform that ought to be suitable to trust to conduct your predive on and assess any in-water issues that occur. You know what the scrubber duration, WOB etc etc is. You know its not going to have a design flaw that the required unmanned and manned tests would have picked up before it even left the factory... Conducting pre-dive checks or flood recovery or bailout or accessing issues underwater etc etc is just a simple evolution and becomes just another drill.

Or do you really care that much about your fellow rb divers? If so thanks for caring...

As far as my diving a rebreather goes, I happily have been able to benefit from an interest in end-user rebreather safety that was commenced by Deep Life as a project back in 2000. and even by the fact that those in Europe got together in 2003 and published the CE standard EN14143 which created a basic level of unmanned and manned criteria for rebreathers to meet.
Nothing about the need to conduct basic unmanned testing on rebreathers before diving them to characters their performance (or identify any obvious design failings) is new as evidenced by the source material used in this blog A Look Inside Rebreather Scrubber Canisters, Part 1 John Clarke Online or the testing that NEDU Search etc etc do on a rebreather before exposing divers to it.

 

[Robert Thompson]

When you can't do the dives you want to do without it. Or the reserve gas requirements (or filling) are insane.

I am bringing 2x hp130s of bailout plus 2 or 3 deco gasses for some upcoming CCR cave dives. There is no way I could haul ~700cf of OC bottom gas plus deco gases into the cave (1km from the car, 100s of km for the nearest commercial compressor) then swim, or even scooter. If you are CCR cave diving with 2 little itty bit Al40s I can do those dives on a set of AL80s and a stage. A rebreather (SCR, CCR, whatever) is just increasing your statistical probability of having some sort of failure. Its not actually allowing you to do anything you couldn't just as easily do on OC.

Some people just like diving CCR. Feel free I'm not saying not to. But I think people should chose the right tool for the dive and go for the actual experience of whatever any given dive offers, not just haul along a bunch of unnecessary gear because its cool.

Or you could use a sidemount RB... Problem solved

---------- Post added December 8th, 2014 at 12:04 PM ----------

better described as a bailout RB.

 

[danvolker]

Amusing and true enough...Another take on the thread is the reaction by the rebreather crowd...very much like walking in to a church, and asking those praying if they believe in God...I don't think the rebreather crowd could be much more dedicated by faith.

Two very distinct sides, just like Christian versus Muslim. There is no arguing against "the faithful"

( I have dived a rebreather...just so you know...


My take is there are good diver candidates for rebreathers...and there are many very bad candidates for them....and the choice of SCR or CCR and specific model needs to become part of the issue with whether the candidate is a good one....along with intended use and frequency of it. And now that it is big business to sell rebreathers, many bad candidates will get rebreather certified, and many bad rebreather instructors will be making a dicey situation worse.

This in no way detracts from your position that someone on this forum, that is good on their rebreather, cant be very safe on some rebreathers.,,it is more about the "masses" that are being sold what is supposed to be a better mousetrap.

 

[Dr. Lecter]

Dan, let's nail down what you're talking about here. I don't think you'll find many people more cognizant of the limits and risks of diving a CCR as safely as reasonably possible, and I personally much prefer OC for its simplicity and ease of use while diving, but at some point the advantages are just too great to ignore.

Let's say we have a group of divers that go out one to two times every week and do a 2-4 hour long decompression dive in the 220'-330' range, here in Hawaii's easy-going waters. They're using 50%-60% helium in their mix, driving DPVs for miles along deep ledges, and spending anywhere from 20-60 minutes at depth depending on their feeling about how long they want to deco for and how many tanks they're willing to lug. Is it really a matter of "faith" to say that for this kind of thing, OC is both more hassle and more risk than CCR? Hell, given the amount of bottles necessary for reserve gas and such, CCR may be a less complex system overall.

I certainly don't claim you cannot do these dives on OC, but it doesn't seem clear to me that it would be safer, and it sure as Hell ain't easier.

 

[boulderjohn]

I certainly don't claim you cannot do these dives on OC, but it doesn't seem clear to me that it would be safer, and it sure as Hell ain't easier.

It was on a day such as you describe that my resistance to rebreathers began to wilt. My buddies and I were diving OC, and there were a couple CCR divers on the boat as well. We had our doubles on our back (Steel 108s for me), and we were each carrying an AL 80 and two AL 40s. It was all I could do to stand up. The rebreather divers, I noted, did not look quite as encumbered.

 

[Dr. Lecter]

My BO requirements often have me slinging up two 80s and two 40s, but damn if that still isn't easier than double 130s and all the reserve/deco gas bottles.

 

[pensacolaracer]

Not to mention the cost of that 30 minute dive to 300 feet on CCR is less than 20 bucks for gas... All in.

I'll let someone else do the math for open circuit with 60 percent helium at 2 bucks a cubic foot for He.

 

[boulderjohn]

Not to mention the cost of that 30 minute dive to 300 feet on CCR is less than 20 bucks for gas... All in.

I'll let someone else do the math for open circuit with 60 percent helium at 2 bucks a cubic foot for He.

You're absolutely right about that--but the rebreather was not exactly free.