The New Dive Rite Optima CM - My 30 Hour Review

[rddvet]

But those are just training dive swimming in circles or doing drills? Or ist that what you guys do for a fun dive? I never spend this long within the first 1500 feet. I want a ccr for deep diving and for logistical reasons.
I thought you do your ccr training in OW, rack up hours and than go into longer cave dives. Isn't that what people do? I thought that was the whole point for getting a ccr.

When I see those people with small BO tanks on their JJs, just swimming the first 900 feet of the Ressel, it seems to me that they are taking more risk for nothing. Maybe I'm missing something here, but don't really get why they would do that. I don't think I would wanna train to dive the breather in a cave... so I assume they're not training. Having said that, I don't know what the normal approach is.

My opinion was similar to yours going into CCR. I thought a CCR was going to be opening up longer and deeper dives, and it can. But just cause you're on CCR doesn't mean you have to go deeper or further. The beauty of the CCR in my opinion is time: time to just enjoy the dive and time to figure out problems. I won't go into a long discussion of CCR safety, but before choosing to dive a ccr (I only chose to initially because my wife needed to dive a CCR for her job/schooling) I had no interest in CCRs because I thought they were dangerous. Now in retrospect I feel just as safe if not safer being closed circuit. I have time and options to fix problems. But back to the actual dives. I have a pfo, so since moving to ccr I have been much more conservative on my dives. One I'm gettting it closed soon and it's just not worth pushing it. Two, the conservatism and moving back to dives with less penetration have been both a great way to really learn to love the ccr and to stoke my interest in the caves more. I was starting to get a little bit burnt out on florida caves. I've done alot of diving in mexico and france, and was losing some of the love for the florida caves. Now I can spend 3 hours in the first 1200 feet of ginnie and just learn to appreciate the cave more. I've found more fossils in the past year in Ginnie than I have in the past 10 years. I've gone into and explored many passages I would usually bypass on OC. It's actually been quite enjoyable.
In cave ccr crossover I was pretty surprised after doing the math by how little distance a set of 50s alone will safely put you in a cave like Ginnie. During the class I thought I'd be selling my 50s and just diving 85s or larger with the CCR. In reality I've enjoyed re-seeing old parts of the cave so much that the distance limits don't bother me because I'm just enjoying the cave more. If I want to go further I can throw on 85s or a stage, but most of the time lately I've just been enjoying simple dives. A CCR can open up deep, far dives but it doesn't have to. Some people would laugh at doing a 2 or 3 hour dive on CCR in peacock. I don't care, I love it. I've got all the time in the world. My dive this weekend on CCr was at P3 and was only 80 minutes long.

[bent]

Thanks, that was interesting to read. One thing though, I can't really follow.

... I had no interest in CCRs because I thought they were dangerous. Now in retrospect I feel just as safe if not safer being closed circuit. I have time and options to fix problems. But back to the actual dives. ...

I've heard this many times over the years from lots of rebreather divers. And I do get the point about having more time to sort stuff out. In that Calimba case or the time when that diver lost his scooter in Ginnie and didn't have enough gas to swim out. In those cases, a ccr might have been helpful.

On the other hand though, there seem to be so many cases in which the diver would have survived on OC. One of them was a buddy of mine. At least 3 more case in the last couple of year I know of. Now, those likey were user error. A ccr gives you more chances to screw up though or at least that's how it looks like to me... and the accident reports seem to suggest that.
I'm far from being a DIR guy but that rule that they had (or still have, I don't know) about only using rebreathers on dives you kind of need one for, makes sense to me... .
I'm kind of surpriesed that you seem to have shortend your dives and started to use the ccr at the same time right after taking fundies.
I wonder what's changed your mind from dangerous to as safe or safer.

[rddvet]

Thanks, that was interesting to read. One thing though, I can't really follow.


I've heard this many times over the years from lots of rebreather divers. And I do get the point about having more time to sort stuff out. In that Calimba case or the time when that diver lost his scooter in Ginnie and didn't have enough gas to swim out. In those cases, a ccr might have been helpful.

On the other hand though, there seem to be so many cases in which the diver would have survived on OC. One of them was a buddy of mine. At least 3 more case in the last couple of year I know of. Now, those likey were user error. A ccr gives you more chances to screw up though or at least that's how it looks like to me... and the accident reports seem to suggest that.
I'm far from being a DIR guy but that rule that they had (or still have, I don't know) about only using rebreathers on dives you kind of need one for, makes sense to me... .
I'm kind of surpriesed that you seem to have shortend your dives and started to use the ccr at the same time right after taking fundies.
I wonder what's changed your mind from dangerous to as safe or safer.

As for dive lengths issue, fundies has zero to do with it. I've been diving my CCR for over 2 years now. I took fundies a month ago. It's a normal progression for most people to back up their diving a little moving to CCR. It's like learning to dive all over again at first. We did a ton of OW dives in the springs post-cert, then did some minor cave dives once comfortable before we took cave crossover (aka the Ginnie card). We didn't want to go all out in the caves before crossover and be those idiots people shake their heads at down the road when they dive in a cave without the certs. Once I took cave crossover we planned to slowly progress our dives to gain confidence in the new setup prior to going all out. During the crossover class Ken and I talked alot about the possibility of me having a pfo. I was tested about 7 years ago but was negative. I never really believed the test results as the ultrasound tech had very little experience with them. Ken and I talked about how I most likely had a pfo, but need a more competent ultrasound tech/dr to diagnose it. Alot of people say once you know for sure you have a pfo, it constantly screams in the back of your head when you're considering a big dive. That's what happened to me after taking class with Ken. Everytime we talked about a long dive with tons of deco I got a voice in the back of my head yelling pfo. Covid hit and it slowed down my ability to go get diagnosed. So we kept the dives to what I consider safe based on my experiences with DCS ( though I took a hit a couple of weeks ago on a routine dive). The pfo is getting fixed the first week of august, so hopefully the beginning of next year I'll be able to start doing more serious, longer deco dives again.

As for safety, I won't go too much into it because there's people with much more experience and knowledge than me. And I won't say much about the deaths either since I don't have all of the information. I will say the deaths I do have intimate details of on ccr mostly seem to be errors made by the diver. Before I started ccr diving, I felt just like you. I'm the stereotypical mid-40s a little overweight guy that seems to like to die on a ccr. I really had zero interest and thought CCRs were dangerous. Then I learned about my unit and it's characteristics that made me feel more comfortable (simplicity, manual unit, dual monitors, and flood resistance). I also didn't want to dive with my primary buddy (my wife) in a mixed team of me oc and her ccr, so decided to take the plunge with her. My initial course focused on highlighting the safety benefits of the ccr in a cave and obviously my crossover did as well. A ccr will definitely kill you with CO2, hypoxia, and hyperoxia, but I think the risks are outweighed by other benefits. The time to deal with a silt out ( you can just sit there and wait all day), entanglement, lost line, or navigational error are huge and outweigh the ccr risks. Add to that things like SCR mode to deal with other issues, and you've got alot of safety positives.
I will say though that I don't believe the safety factor holds true for all unit. I was lucky to pick as my first unit one that I believe is set up very well and gives me confidence in my safety diving it. I am trained on another unit I won't name here because I will get slaughtered by the fanboys, that I believe is a huge POS and in in my hands is wholly unsafe and will kill multiple people before a law suit occurs and makes the company adapt the unit. I went from believing ccrs were unsafe to then being fully confident in the safety of the unit I dive (with a hearty side dose of understanding there are safety issues that could pop up that wouldn't on oc). Then I took the class on the other unit and fully understood why so many joke that your unit is trying to kill you. Because that's what I felt with that other unit after taking a small CO2 hit on it.

[bent]

... As for safety, I won't go too much into it because there's people with much more experience and knowledge than me. And I won't say much about the deaths either since I don't have all of the information. I will say the deaths I do have intimate details of on ccr mostly seem to be errors made by the diver. Before I started ccr diving, I felt just like you. ...

I don't have all the information either. I don't think there is anybody who does. It's just seems odd to me when people say that CCRs are just as safe as OC when we all see that a fairly high number of accidents seem to happen on ccr. I've never heard anyone explain that 'as safe logic' beyond the point that you have more time. Honestly I don't think there is any logic behind it. I'm sure people are well aware that rebreathers are more dangerous but just don't wanna talk about it... one reason is probably business related. The number of people for whom a ccr would make sense is probably pretty low.
For the dive you and Jim are describing, I really wouldn't wanna be on a breather, but I do appreciate your explanation. Sorry to hear that you got bent.

[Texas Torpedo]

thanks for the evaluation... I know nothing about rebreathers but it looked cool. I would definitely like to try one someday.... the concept of the loop being in front of me is one I like as I tend to get claustrophobic with gear running all around my body.

You are claustrophobic and a cave diver?

[bamafan]

You are claustrophobic and a cave diver?

There are some. They generally stick to the bigger passages and the ones that I have met are usually extremely conservative.

[Diverlee]

There are some. They generally stick to the bigger passages and the ones that I have met are usually extremely conservative.

I know a few that just do not like small tight areas. They do the same.


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[rddvet]

I have no claustrophobia in the caves or in the water, but I do have a weird claustrophobia thing. I cant put my mask on until the dives starting. Some people can put their mask on and sit and bs on the surface for 5 minutes. If i do that I get claustrophobic. I do everything I need to do and put my gear all in place, and mask is absolute last thing. Once in the water I?m 100% perfect and have never had any claustrophobia in any other situation. Im a heavy nose breather which I?ve had to learn to control diving. My hypothesis is that not being able to nose breathe on the surface subconsciously messes with my brain. I?ve been stuck in tight restrictions with no issue.


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[cavemark]

I’m claustrophobic in dry caves. Can’t go more than 50’ before my brain says ‘no way’. 4,500’ in the back of Ginnie or 20 minutes of penetration in eagles nest and the only thing I was thinking was ‘crap. This deco is going to be boring’. Even a total silt out doesn’t trigger it.

[PsychDiver]

Before I swam it for the first time I got kind of heeby-jeebied watching video of Rocky Horror, but when I got in there I was fine, and have never had issues actually being in modestly snug places (e.g. one tank off getting in to crossunder). Must have to do with the focus. You won’t find me rock climbing though — not fond of heights.