narrow my options

[rjack321]

The JJ is an awesome rebreather, very simple but very solidly built. Lots of divers doing big dives use them.

I think the JJ is worth considering for the OP, but IMO its not functionally different than any other solenoid driven tube scrubber with a external counterlungs. The XCCR, liberty or a Meg would be basically the same - the big difference with the JJ is with the annoyingly rare cell connectors.

 

[doctormike]

I think the JJ is worth considering for the OP, but IMO its not functionally different than any other solenoid driven tube scrubber with a external counterlungs. The XCCR, liberty or a Meg would be basically the same - the big difference with the JJ is with the annoyingly rare cell connectors.

Right, I was just thinking that since he had 3 buddies with JJs, that might tip the decision a bit. Haven't had any problem getting the cells, and those connectors are supposed to be pretty solid. But I don't know much about other units...

 

[rjack321]

Right, I was just thinking that since he had 3 buddies with JJs, that might tip the decision a bit. Haven't had any problem getting the cells, and those connectors are supposed to be pretty solid. But I don't know much about other units...

I think you can get molex to coax adapters. Its probably worth looking into that if you travel a lot. Finding a spare molex cell is relatively easy compared to finding a spare coax - since molex cells are used in more units than coax. But if he has buddies with JJs they could bring a full set of 3 spare coax cells on trips for efficiency.

 

[tbone1004]

@rjack321 the JJ is a LOT cheaper than an X or a Meg though. Liberty is similar price, but the X and Meg's are stupidly overpriced IMO.

N@90 sells an adapter but I think they're like $20-$25, but best way is to keep the bits for a molex plug, and since the JJ has wires coming out of its cells, just snip the wire off the cell when the first one dies and solder the molex on there. Costs like $2 if you can solder. Make a handful of them as the cells die on the offchance that you need them, and you're good to go

 

[DA Aquamaster]

Because a sidemount CCR is a highly specialized piece of kit that does some things great - and other things horribly. If you want to dive small caves but aren't especially far from the entrance, a SM CCR is ideal.

Deep caves can be hit or miss, but especially for open water dives at significant depths (eg 100m), a sidemount CCR is awful - there is no place to put the bailout. For a dive like that, you're looking at least 3 and probably 4 BO cylinders (plus suit gas). A backmounted CCR is way more versatile and there are actually enough places to stash those BOs, although once you get past 2x al80s its not as easy as it sounds.

Get the right tool for the job. Someone who is planning deep wreck trips but isn't even cavern certified yet should probably be in a backmount CCR. Only people who don't know what they are talking about say "But I don't want to buy twice". The reality is that you need more than one unit (and the backmount vs sidemount SF2 is for all practical purposes two units since the conversion is quite elaborate) to do different dives well (or even at all).

I agree that SM CCR is great for small passage caves and for caves where you are only a couple thousand feet from an entrance or have the ability to make a couple set up dives to pre-place most of your bailout.

I agree that it is also not ideal for deep offshore dives, however you can make it work if you only do those dives on an infrequent basis. For example, I still have a Nomad sitting in the garage and I discovered that if I use the Nomad with a set of back mounted doubles for the diluent / primary bailout, I can run the Sidekick on my right side (where I run it anyway) and then carry an AL80 stage of bailout travel /first deco mix on the left side and an AL 40 of bailout O2 on either the left or right side. It ends up being pretty much the same as a normoxic trimix OC dive in terms of carrying the gas. You're just back mounting most of the your bailout gas.

Now...that still leaves you with the problem that what makes an ideal diluent isn't always the same as what makes an ideal bailout gas, which is one of the issues you just have to accept with any sidemount CCR where the diluent is all off board. You can work around that too however if you go with an iconel sphere on the bottom of the unit for O2, and then a 3L dil bottle on the side of the unit - which also works well if you run a Sidekick as a stand alone BoB.

 

[DA Aquamaster]

so I need help please from ccr divers on narrowing my purchase options-

My primary interest is wreck diving - im about to do a cavern course for future cave diving options so side mount ccr is a sensible option- however the advice from sales people is its hard to go from OC to a sidemount ccr without having a back mount first- not sure if this a sales pitch or genuine. The SF2 has a back mount option which can convert to side mount - not sure if theres any others..../

Overall I'm in near total agreement with Richard that a Side mount CCR is not what you want. Not now. Maybe not ever.

It's not ideal for offshore. I can make a side mount CCR work in that role, but it's not ideal, and we do very few deep offshore dives anyway. If it was my primary interest, I would not have went the side mount CCR route at all.

Marci and I converted from OC side mount to CCR side mount and skipped the back mount CCR since it didn't make much sense for us to move back to a back mount configuration after 7 or 8 years of side mount OC diving, given that we intended to use the CCR in the same small passage cave environment where side mount made sense. And we still dialed are cave diving way back in terms of penetration and difficulty for 100 hours or so after our CCR class.

If we had not had extensive SM experience we would have went back mount CCR first, got a couple hundred our of time in back mount CCR and then converted to side mount CCR In that regard, unless you have a lot of side mount experience, I doubt you'd be able to find an instructor who would cross you over all the way from back mount OC to side mount CCR.

In your case, unless you are going to do actual side mount cave diving, rather than cave diving in a side mount configuration, you probably should not, and would not want to go with a side mount CCR.

 

[rjack321]

@rjack321 the JJ is a LOT cheaper than an X or a Meg though. Liberty is similar price, but the X and Meg's are stupidly overpriced IMO.

Define "a lot"?? New prices I could quickly find but I didn't try to match what's included vs sold separately...

$9,000 for a JJ
JJ CCR Rebreather *Buy JJCCR at DIVESEEKERS.com 888-SCUBA-47

$9,000 for a Liberty
CCR Liberty - fault tolerant rebreather

$9300 for a Defender
Defender CCR - SubGravity

$9300 for a Meg15
Meg 15 Complete - Innerspace Systems Corp

$10,000 for an xCCR
X-CCR - SubGravity

They are still all backmounted tubes with 2 or 3L cylinders on the sides, ~5 to 6 lb axial scrubbers with radial options, external counterlungs, and a solenoid in the head. Not seeing them as all that functionally different from one another in the grand scheme of things. Any of them would work for the OPs dive goals (plus others including the Revo and SF2 which are a bit different in the counterlung department especially).

 

[JohnnyC]

I currently have two rebreathers, owned 3, tried several others. The only "mistake" was my first rebreather. It wasn't really a mistake, but it didn't fit my needs as well as I thought it would. It took buying a world-class rebreather, diving it, being less than impressed, and seeing what I REALLY wanted in a rebreather, before I finally figured out just what direction I wanted to go. I'm happy with the two rebreathers I currently own, and wouldn't own any of the other rebreathers currently on the market. It's not because my two rebreathers are the best, or the other rebreathers on the market suck, but for my own personal diving, my two fit best for what I want to accomplish.

You'll find as you try several units, you'll figure out exactly what features you want, what you don't, how a great idea can actually be really poor in practice, how features you thought would be amazing are really unnecessary, and ultimately you may figure out that there's no perfect rebreather for you, so you figure out which checks the most boxes. Or, you figure out which checks the most boxes then hack and slash and burn and add and everything else until it's exactly the way you want it. It's a process, but you don't want to blindly jump in with both feet.

I think the SF2 is the best option on the market in terms of a convertible rebreather. It works very well as either BM or SM, the conversion is easy, and relatively inexpensive.

 

[tbone1004]

@rjack321 the Meg and JJ are the only ones that have axial as an option. The other two come standard with radials and only have options for radials.

configure the Meg or the X similar to the stock configs of a liberty. Meg jumps to $12500. Have to put the radial scrubber, second handset, 3l steels, wing, spare parts kit, and a canister cover on there. X comes out to like $11300 with the same options selected.
JJ has a $500 radial scrubber, but it's in addition not in lieu of. Unsure if you can order with just the radial, and then have to have a second handset to match the Liberty which is probably another grand, but either way, the Meg and X come out $1k-$2k more than the JJ comparably equipped, or $2k-$3k more than the Liberty comparably equipped.
Doesn't make them bad obviously, I have a Meg, but they are considerably more expensive and don't really give you anything that the Liberty or JJ can't

 

[lermontov]

Overall I'm in near total agreement with Richard that a Side mount CCR is not what you want. Not now. Maybe not ever.

It's not ideal for offshore. I can make a side mount CCR work in that role, but it's not ideal, and we do very few deep offshore dives anyway. If it was my primary interest, I would not have went the side mount CCR route at all.

Marci and I converted from OC side mount to CCR side mount and skipped the back mount CCR since it didn't make much sense for us to move back to a back mount configuration after 7 or 8 years of side mount OC diving, given that we intended to use the CCR in the same small passage cave environment where side mount made sense. And we still dialed are cave diving way back in terms of penetration and difficulty for 100 hours or so after our CCR class.

If we had not had extensive SM experience we would have went back mount CCR first, got a couple hundred our of time in back mount CCR and then converted to side mount CCR In that regard, unless you have a lot of side mount experience, I doubt you'd be able to find an instructor who would cross you over all the way from back mount OC to side mount CCR.

In your case, unless you are going to do actual side mount cave diving, rather than cave diving in a side mount configuration, you probably should not, and would not want to go with a side mount CCR.

Thanks for that info -actually sidemount ccr IS what i want -ive just got back from a trip having dived with my buddies one on an inpso another on a JJ- neither of them could get to places i got to on my OC sidemount - my dilemma is making the jump from OC to CCR and has been accurately pointed out that there are different tools for different dive objectives - In an ideal world i would have have multiple dive tools - and yes you may be right, maybe a JJ ( or other) is the right tool to start (and keep for deep dives)and then buy another brand of sidemount ccr to do the wreck dives. Im planning on trying different ccrs to get a 'feel' for what i like and if it means I have to 'dial back ' my wreck penetrations until I gain enough skill then so be it

BUT -if going to a ccr meant it would stop me ( indefinitely ) doing the penetration diving Im currently doing then I wouldn't buy one- so in effect i am committed to that track

I haven't got the years of sidemount penetration diving that you have but how much is enough ? is volume the criteria? or is it difficulty? Ive seen divers with 500+ dives who are a shambles.