First rebreather JJ or Choptima

[Rollin Bonz]

Thanks. That makes sense. I did a try dive and didn't bottom it out, but I was also only at 15-20 ft.

I remember liking it after the try dive, but was little concerned with the chest clutter since that's something that I didn't pay attention to during the try dive

Depth should have no effect as you (or your ADV) will add dil to the loop to maintain CL volume as you descend. If dil is NOT added your CL WILL bottom out on its own as the volume compresses as you descend.

After 3 years, I do not register the Choptima as clutter on my chest. I'm not certain I ever did. However, as previously mentioned, I am of larger stature.

 

[JackZwykle]

Going to be getting my first CCR and debating between a CM or BM unit. Have narrowed it down to a JJ or a Choptima. Not going to be traveling much with it, so that advantage of a Choptima isn't such a big deal. My buddy has decided that he's going to get a JJ. Based in SFL. Most of my dives are wreck diving with advanced penetration. Usually in warm water but some months of dry suit diving. Do deco dives up to 150' now but will definitely be going the MOD2 route after 50-100 hours on the unit to dive some deeper wrecks. Not sure if MOD3 is in the future yet, that's quite a ways off. Was thinking that because I'm going to be doing MOD2 will have to sling a bottle regardless of if I use my back mount doubles as dilout with either 50 or 100% so with a Chop I would have backmount doubles, Chop plus that AL80 vs the JJ would have 2 bailouts.
How big of a deal is the chest clutter with the Choptima and loss of the chest D rings? Access to dry suit inflator? Any other pros or cons of one unit over another? Or anything else that I'm not thinking of?
Thanks for the help

1. You answered yourself in the 4th sencence.
2. The unit that your buddy and local community dives most (looks like JJ).
3. Still the unit of your buddy.
4. As for Choptima - never dived it, but saw it in action, know the possibilities - very impressive unit and I like how it can blend into traditional BM cylinders. However what almost no-one ever discusses is the Stress Velopharyngeal Insufficiency - fastest happening with CM... there is a reason for CM rebreathers to be the first in history and then abandoned for BM and OTS.
5. JJ is the Land Rover of CCR - not the cutting edge, but one of the most robust and configurable units out there (bar CM). I have them all around me, they just work. The only unit to provide an option for an active heated scrubber AFAIK.

I don't dive either, just my 5 cents (and points 1-3)

 

[mr_v]

If you're not doing sub 400' dives, consider a rEvo. There is plenty of them in SE FL and they are great on boats. Remarkable US based support from Mares right in SE FL makes rEvo stand out.

You're hours away from getting parts and as rEvo's headquarters are in Europe, you'll have close to 24-hour customer service. As Mares has enough capital to carry inventory, you won't be waiting for days to get most of the parts. You will also have a unit that you can service yourself.

 

[Dsix36]

If you're not doing sub 400' dives, consider a rEvo. There is plenty of them in SE FL and they are great on boats. Remarkable US based support from Mares right in SE FL makes rEvo stand out.

You're hours away from getting parts and as rEvo's headquarters are in Europe, you'll have close to 24-hour customer service. As Mares has enough capital to carry inventory, you won't be waiting for days to get most of the parts. You will also have a unit that you can service yourself.

No need to limit the rEvo to sub 400'. Many have been much deeper. Mine took me below 600'

 

[mr_v]

No need to limit the rEvo to sub 400'. Many have been much deeper. Mine took me below 600'

I read the blog post. The reality is that I'd probably get a diff breather, and I love my rEvo.

 

[boriss]

Going to be getting my first CCR and debating between a CM or BM unit. Have narrowed it down to a JJ or a Choptima. Not going to be traveling much with it, so that advantage of a Choptima isn't such a big deal. My buddy has decided that he's going to get a JJ. Based in SFL. Most of my dives are wreck diving with advanced penetration. Usually in warm water but some months of dry suit diving. Do deco dives up to 150' now but will definitely be going the MOD2 route after 50-100 hours on the unit to dive some deeper wrecks. Not sure if MOD3 is in the future yet, that's quite a ways off. Was thinking that because I'm going to be doing MOD2 will have to sling a bottle regardless of if I use my back mount doubles as dilout with either 50 or 100% so with a Chop I would have backmount doubles, Chop plus that AL80 vs the JJ would have 2 bailouts.
How big of a deal is the chest clutter with the Choptima and loss of the chest D rings? Access to dry suit inflator? Any other pros or cons of one unit over another? Or anything else that I'm not thinking of?
Thanks for the help

Are you already AN/DP and diving deep wrecks (tech trips)? If so, you should be seeing tons of rebreathers. The boats I'm on are majority rebreathers. On a regular basis, I dive with people who own: Choptima, JJ, rEvo, XCCR, Liberty, GBM, Meg, etc. We all go to the same wrecks and do the same penetrations. The real question is which configuration is right for YOU?

I dive Choptima, but can see myself on any of those other units, for various reasons. It's all pros and cons. If there were one that were perfect, we'd all be diving it.

Go on technical dives, look at the configurations and talk to the owners. Everyone has a different reason for why their unit is the best for them.

I promise you, no matter which unit you'll end up with, you'll be envious of another for one reason or another. It's like choosing between a truck, an SUV, a sports car and an economy car. Which is best? Get both

 

[bipolarbear]

I have been in a similar position to you, doing similar (perhaps somewhat deeper) OC tech profiles, and I settled on the JJ. I start my Helitrox Mod1 course in about 3 weeks.

Choptima was really enticing to me. I love the idea of being able to just strap it on and keep my doubles configuration with long hose / necklace etc. But for the kind of diving I do (open ocean or wrecks, with ambitious in the 100m/330ft range) the JJ won it for me. Plus most everyone I know in my region dives a JJ.

 

[JJCC]

following...

 

[SmashMonkey]

Going to be getting my first CCR and debating between a CM or BM unit. Have narrowed it down to a JJ or a Choptima. Not going to be traveling much with it, so that advantage of a Choptima isn't such a big deal. My buddy has decided that he's going to get a JJ. Based in SFL. Most of my dives are wreck diving with advanced penetration. Usually in warm water but some months of dry suit diving. Do deco dives up to 150' now but will definitely be going the MOD2 route after 50-100 hours on the unit to dive some deeper wrecks. Not sure if MOD3 is in the future yet, that's quite a ways off. Was thinking that because I'm going to be doing MOD2 will have to sling a bottle regardless of if I use my back mount doubles as dilout with either 50 or 100% so with a Chop I would have backmount doubles, Chop plus that AL80 vs the JJ would have 2 bailouts.
How big of a deal is the chest clutter with the Choptima and loss of the chest D rings? Access to dry suit inflator? Any other pros or cons of one unit over another? Or anything else that I'm not thinking of?
Thanks for the help

I started asking the same question a year ago. I fly everywhere to dive so I'm leaning toward Choptima. Have you dived with Horizon Divers in Key Largo? The instruction is excellent and Dan Dawson (owner) teaches JJ and Jeff Knapp (manager) teaches Choptima. Almost all the CCR divers on their boats dive one or the other. I spent the last year just talking to Dan and Jeff and all divers I've met and getting their opinions pro and con and seeing how they dive.