The big question about ccr… which one

[Tracy]

I dive the BM Optima and have no real complaints about the unit. I chose it due to the number of Optima divers that are around my area and there is a good instructor local to me. Most everyone I dive with that is on a rebreather dives an Optima and we share spares amongst each other when the needs arises. Biggest thing is to look around and see what other people are diving and ask them why they went with their particular unit.

Where did you find a good instructor? I thought I was the only one around?

 

[Superlyte27]

As many of you know, I was once taken in by great marketing on a terrible rebreather. As soon as I learned the error of my ways, I became certified on nearly every popular rebreather. By 2023 I’ve owned over 30 rebreathers. Right now, I own 6 and dive 4 of them.

For those of you that don’t know me, you might say, “Well, you’re going to push the rebreathers you sell”. For those that do know me, well… you know that I don’t need to sell anything.

With that said, there is no one perfect rebreather. I wish there was. There isn’t. I have a perfect rebreather for travel and wreck diving. It’s the Choptima. I have the perfect rebreather for spear fishing, it’s the Optima. I have a decent rebreather for tight caves, it’s the sidewinder (and the closest thing to perfect right now for tight caves, but not perfect).

With all that said, for me, a cave diver who occasionally dives wrecks and very deep. If I was only going to have ONE rebreather, it would be the back mount Optima. For a bunch of reason….

Great WOB
Super Flood Tolerant
Super Easy to Build and Repair
Best Customer Service that rivals Shearwater
Shearwater
ECCR
Clear Chest for Spear Fishing
Will go long and deep
It’s never cost me a single dive ever. It just always works.

Ftr, I haven’t sold a back mount optima in years. Everyone is buying thr Choptima and I think it’s had the highest 24 month sales numbers of any rebreather ever and I own 2 of them. That’s not by accident. But, I can’t spearfish on it. I’m a fat guy who doesn’t want another 4” on my chest (lol). It’s okay for scootering, not great. It breathes good, it’s lightweight, it’ll go very deep (I hold the record at 487’) but it won’t do absolutely everything I want it to do. No rebreather will.

FYI, MCCR sucks. Have a buddy go catatonic at 190’ while you’re on MCCR and let me know how much fun it is getting him back to the surface while maintaining his wing, drysuit and loop volume and maintaining your wing, drysuit, loops and ppo2 while ascending. Remember, your PPO2 is crashing as you ascend from 190’ on MCCR, your hands are full saving your buddy, but oh wait, I have to constantly deal with my PPO2 at the same time. No thanks.

 

[broncobowsher]

Just reading InDEPTH’s Holiday Rebreather Guide 2023
And a very good part to think about is...

It’s The Concept, Stupid​

The plan was to focus on the feature sets of the various rebreathers to provide an objective means to compare various units. But features by themselves do not a rebreather make. As Pieter Decoene, Operations Manager at rEvo Rebreathers, pointed out to me early on, every rebreather is based on “a concept,” that is more than just the sum of its features. That is to say that the inventors focused on specific problems or issues they deemed important in their designs; think rEvo’s dual scrubbers, Divesoft’s redundant electronics, or integration of open and closed circuit in the case of Dive Rite’s recently launched O2ptima Chest Mount. Shoppers, please consider that as you peruse the various offerings. My thanks to Pieter, who helped us identify and define key features and metrics that should be considered.

 

[happy-diver]

Start off slow and learn fast check this out

RD1 Rebreather - Kit System (Back Mount)

The 'Rebreather Day 1' (RD1) 'kit' provides open-architecture components to allow a very easy build-out for those already RB-savvy. Our recommendation is to first configure the unit as a simple oxygen only system which is depth limited to 20 feet/6 meters depth. Once proficiency is attained, the...

www.underseatools.com

"The 'Rebreather Day 1' (RD1) 'kit' provides open-architecture components to allow a very easy build-out for those already RB-savvy.

RD1 Rebreather - Kit System (Back Mount)​

Regular price$1,758.93

Our recommendation is to first configure the unit as a simple oxygen only system which is depth limited to 20 feet/6 meters depth. Once proficiency is attained, the open architecture allows for easy customization to SCR, CCR, and other integrated systems."



Yeah not being from Merca I was interested in the Triton years ago and interested in rebreathers for decades

Wasn't so interested in the price and built my own instead

And just missed the most magnificent five ocean diving days on the planet, working

Not so magnificent!

From this

Magnificent!

 

[DanFromDownUnder]

Everyone knows the best rebreather is the one you own.

The way I went about choosing my rebreather was to reach out to friends who were rebreather instructors and asked them each what their top 3 rebreathers were and why and instructors other than themselves they would recommend for each of them. Then I talked to those instructors. I found an excellent instructor in North Florida cave country who let me train on the rebreather before I committed to spending 10k on a new toy. (i actually ended up getting a 2nd hand unit barely used.)

Definitely do some try dives on the different units you can get your hands on. And don't be surprised if you hate diving it for the first couple days of your training.

 

[GiraffeMarineSalvage]

FYI, MCCR sucks. Have a buddy go catatonic at 190’ while you’re on MCCR and let me know how much fun it is getting him back to the surface while maintaining his wing, drysuit and loop volume and maintaining your wing, drysuit, loops and ppo2 while ascending. Remember, your PPO2 is crashing as you ascend from 190’ on MCCR, your hands are full saving your buddy, but oh wait, I have to constantly deal with my PPO2 at the same time. No thanks.

I'm admittedly not yet at the point of diving 190' but safety record of mCCRs was noteworthy to me when looking at accident statistics prior to purchasing my mCCR, it seemed like eCCR naturally encourages deviation from core rule of "always know your PPO2" because everything is taken care of until it isn't...
Personally the "simplicity" & robustness plus good habit forming nature of a well made mCCR in which Petrel+Nerd tell me what I need to know to make informed decisions still wins out for me, especially due to inherent limitations of galvanic cells.

(With that said, I could pretty easily be swayed over to eCCR camp for a potential future CCR if financially justified based upon same prioritization of "simplicity" & robustness of an eCCR with two solid state sensors if/when Shearwater embraces solid state sensors but I would make PPO2 setpoints wide enough to run it manually with needle valve by habit, as well as making subtle buoyancy changes by adjusting my loop volume, and considering the solenoids as a backup in case of being heavily task loaded resulted in my failing to manually keep PPO2s within a proper range...)

 

[AJ]

Personally the "simplicity" & robustness plus good habit forming nature of a well made mCCR in which Petrel+Nerd tell me what I need to know to make informed decisions still wins out for me, especially due to inherent limitations of galvanic cells.

There's an opposite view to this. What if you're in a situation where the sh*t really hits the fan. Are you able to manage your mCCR PPO in that situation next to surviving or would you appreciatie a little help from your rebreather taking care of your ppo?

There's no definite answer as far as I'am concerned. Both eCCR and mCCR have their strength's and weaknesses. Other considerations are just as important. You can find the perfect ccr for your needs, but that does not mean it's the best ccr in the world to everybody.

 

[Wibble]

There's an opposite view to this. What if you're in a situation where the sh*t really hits the fan. Are you able to manage your mCCR PPO in that situation next to surviving or would you appreciatie a little help from your rebreather taking care of your ppo?

There's no definite answer as far as I'am concerned. Both eCCR and mCCR have their strength's and weaknesses. Other considerations are just as important. You can find the perfect ccr for your needs, but that does not mean it's the best ccr in the world to everybody.

And then there's hCCR -- Hybrid CCR -- which offer the best of both worlds: an orifice constantly injecting oxygen from a mCCR, and a solenoid+controller to inject oxygen from an eCCR.

This is great as the orifice stabilises the oxygen levels, reducing the number of times the oxygen solenoid fires. It encourages you to run the unit manually, thus really understanding what's going on, but having a parachute; the controller looking out for you should you be distracted.

The Revo is the only hCCR unit that I know of. Great to dive.

 

[GF99/99]

FYI, MCCR sucks. Have a buddy go catatonic at 190’ while you’re on MCCR and let me know how much fun it is getting him back to the surface while maintaining his wing, drysuit and loop volume and maintaining your wing, drysuit, loops and ppo2 while ascending. Remember, your PPO2 is crashing as you ascend from 190’ on MCCR, your hands are full saving your buddy, but oh wait, I have to constantly deal with my PPO2 at the same time. No thanks.

Totally agree this is not ideal and on an eCCR it is much nicer for a situation like this. And on an mCCR your absolutely correct you need to be prepared to be put in this situation making this one of the deciding choices of an mCCR. BUT........

Was this not part of your training and continued training?
I know I had to do this exact thing from 70m as apart of my training. Unresponsive diver rescue from depth (as far as I know this is standard in almost all courses I had to do it 7+ different times with different variations in mod 1, mod 2, mod 3 and ANDP, Extended Range, Trimix, and Adv. Trimix), and then you reverse the role with your dive buddy taking the course with you. Even had to play the game of my computer is broke so now I have to fly off my HUD while bring up my unresponsive buddy, maintaining my mCCR off the HUD, his mCCR, my wing, his wing, my suit, his suit. Oh and don't forget have to send up a yellow SMB too.

This is something between my dive buddies we practice to keep our skills fresh as this is one of the more difficult skills that is actually can really happen, I am assuming other CCR divers randomly practice skills and drill too???? (or maybe me and my dive buddies are weirdos). Same with complete loss of buoyancy (wing splits/fails) its a mission to dive a super inflated suit or ride a bag up and do all your deco stops so worth practicing). And same for bail out at depth although we just take a 2-3 breaths off the regs to simulate a B/O due the crazy high cost of He but it is worth B/O out to OC at 140m to test it.

 

[GiraffeMarineSalvage]

There's an opposite view to this. What if you're in a situation where the sh*t really hits the fan. Are you able to manage your mCCR PPO in that situation next to surviving or would you appreciate a little help from your rebreather taking care of your ppo?

That's why I was alluding to easily jumping into eCCR or hCCR if/when solid state sensors are supported by Shearwater..

In practicing ascent with "unconscious" diver along with other practice scenarios at shallow depths I personally didn't find it difficult to manage Triton mCCR PPO2 (fully acknowledge a real emergency would inherently be a higher mental task loading...).

BUT regardless of CCR type, if sh*t really hit the fan I'm probably (almost definitely) bailing out... Completely scenario dependant of course, and will note at this time I'm nowhere near doing dive profiles that need a backup rebreather as opposed to OC bailout, but many of the hypothetical "worst case" scenarios I've thought through include much higher CO2 production towards the end of a dive, ie less margin of error in terms of scrubber resistance to breakthrough...
Last thing I want to add to whatever emergency was already being delt with would be a CO2 hit due to hard physical activity towards end of stack time (even though the scrubber had "plenty" of capacity for leisurely resting at a deco stop...)