Lightest and most popular RB

[rjack321]

I think I would take popular out of your equations. As long as its commercially made by a company here to stay who cares if there are 200 or 2000 units on the market at the moment? What everyone else is or isn't diving is rather irrelevant to me.

That leaves weight as a top consideration, the kiss orca lte is just about the lightest possible. Based on my experience with its sister the sidewinder I would say you can expect:

manual (no solenoid)
light weight (source lead and BO at your destination)
great breathing
dirt simple but has some proprietary parts
easy to field repair/adjust
poor water/flood tolerance
modest cold water performance
~80m depth limitation in stock configuration (not really a 100+m dive kind of unit anyway)
easy to break down and pack in a carry-on

you can also readily get training in the USA and Canada.
Not CE certified so diving one in someplace like France could be a hassle depending on the dive shop etc.

 

[kensuf]

OMG: Nicely described. Loved the part about going on subway with small tanks. Points about complexity and simplicity well taken. An elegant easy to service design is my optimal set. It is subjective of course.

I own an SF2 and a Fathom, I've previously owned a KISS Classic and I'm also certified on a couple of other rebreathers that are fairly well known. With close to 600 hours on rebreathers right now, the one thing I've learned is there is no magical rebreather that does everything well and they all involve a trade-off of some sort.

Simplicity and complexity can mean different things to different people.

Are we talking assembly/disassembly?

Are we talking maintenance?

Are we talking design?

Are we talking operation?

The SF2 is incredibly simple to assemble and disassemble. But because of the electronics and being an eCCR, maintenance on the head is more complicated than others -- I can't fix something with the electronics pod, it has to go back to the service center.

My KISS Classic was a pain in the butt to assemble, but with no electronics, diving it was fairly straight forward. If something broke on the KISS, most of the replacement parts could be found at any Lowe's or REI.

My Fathom is somewhere in between. Assembly/disassembly is nowhere near as complex as the KC, but assembly is more time consuming than the SF2. On the other hand, cleaning and maintaining the Fathom is basically as simple as taking the cells out of the head (30 seconds) and dropping the head in a bucket of water. Being an MCCR, diving it is fairly simple in the water too.

Other units that I'm certified on (or otherwise fairly familiar with) include the JJ, Optima, Hammerhead, and Meg. Those are all more complicated to assemble than the SF2, are all electronic units, which mean additional batteries for the solenoid, an added failure point in the solenoid, an electronics pod that can't be easily fixed without going back to the factory, and the pros and cons that come with diving an eCCR (having the parachute is nice, until it does things you don't want it to do).

On the small compact thing. Every unit I have owned had 3L cylinders that you can carry in a messenger bag. That is nothing special or unique.

The "light" thing may make sense if you're traveling, until it doesn't make sense. My SF2 is very "light" (it's made out of carbon fiber!), but when I fly with it I have it in a large pelican case that goes in as checked baggage because although it's all compact in one tube, it won't fit easily as carry on. My Fathom, which is heavier on dry land, is small and compact, will fly as carry-on with me. I have friends that carry their JJ's on with them, even though they are some of the heaviest units out there.

My recommendation is if you are dead set on a rebreather, find an instructor that actively dives and has experience on multiple rebreathers, get your hands on a used unit with the idea that you will likely be selling that unit in a year or two, and get some experience on a rebreather. Once you've been diving a rebreather for awhile you will have a better idea of what elements are important to you in a CCR.

best of luck,

Ken
ps - I have a line on a really incredible KISS Classic with a petrel 2 if you're interested.

 

[rddvet]

My Fathom is somewhere in between. Assembly/disassembly is nowhere near as complex as the KC, but assembly is more time consuming than the SF2. On the other hand, cleaning and maintaining the Fathom is basically as simple as taking the cells out of the head (30 seconds) and dropping the head in a bucket of water. Being an MCCR, diving it is fairly simple in the water too.

I knew the cells were on a removable tray to dry and that the electronics in the head were potted, but didn't realize it was "safe" to dunk the head for regular cleaning. With the top and the bottom of the body coming off, it seems basically the whole unit can be taken apart and submerged minus counterlungs and cells.

I'm ponying up the bucks next month for Charlie to start building us two of them.

 

[broncobowsher]

Revo is another one that is fairly popular and can be carried on when flying. While not the lightest, it is on the lighter end of the scale.

 

[JohnnyC]

Revo is another one that is fairly popular and can be carried on when flying. While not the lightest, it is on the lighter end of the scale.

Sure, but then he'd be stuck with a revo.....

 

[kensuf]

I knew the cells were on a removable tray to dry and that the electronics in the head were potted, but didn't realize it was "safe" to dunk the head for regular cleaning. With the top and the bottom of the body coming off, it seems basically the whole unit can be taken apart and submerged minus counterlungs and cells.

I'm ponying up the bucks next month for Charlie to start building us two of them.

The cells aren't in a removable tray. Each cell screws into the head individually. But it's a 30 second operation to remove all 3 cells. Another brilliant thing with the Fathom is that whenever you do either a DIL or O2 flush, the gas shoots across the cell faces of cells #1 and #2, thus drying them.

Next time you're at CCDS, ask to see Jon's Fathom head. It's currently sitting on the middle bench/table between the haskel and Jerry's work-bench. It's a first gen, the second gen (like mine) have the piezo for the HUD built into the head.

Speaking of HUDS.. Aside from cross-overs / try dives, I've never really spent much time on units with HUD's until now. I had a NERD for awhile (hated it), but the simplicity of the 3 LED HUD with the Smithers codes (same guy who made the TP2000) is brilliant. Absolutely love it.

 

[688ClassRebreather]

@doctormike local popularity 100%, but not overall popularity.

Divesoft has a US distributor and a handful of instructors in Florida. I know of 4 offhand, but definitely centralized in Florida right now. The unit is REALLY slick though....

I don't dive the Liberty, but I have several friends who do. There are a few Liberty instructors in Hawaii. It is pretty nice.

 

[tbone1004]

I don't dive the Liberty, but I have several friends who do. There are a few Liberty instructors in Hawaii. It is pretty nice.

there's one, who is currently under investigation after a death of one of his employees/students.... I would recommend avoiding that shop personally

 

[JohnnyC]

there's one, who is currently under investigation after a death of one of his employees/students.... I would recommend avoiding that shop personally

Same shop as ol' "derrick poodle?" I don't want to use his real name, dude shouldn't have any more publicity.

 

[rddvet]

The cells aren't in a removable tray. Each cell screws into the head individually. But it's a 30 second operation to remove all 3 cells. Another brilliant thing with the Fathom is that whenever you do either a DIL or O2 flush, the gas shoots across the cell faces of cells #1 and #2, thus drying them.

Next time you're at CCDS, ask to see Jon's Fathom head. It's currently sitting on the middle bench/table between the haskel and Jerry's work-bench. It's a first gen, the second gen (like mine) have the piezo for the HUD built into the head.

Speaking of HUDS.. Aside from cross-overs / try dives, I've never really spent much time on units with HUD's until now. I had a NERD for awhile (hated it), but the simplicity of the 3 LED HUD with the Smithers codes (same guy who made the TP2000) is brilliant. Absolutely love it.

Oh I thought the tray came out too. I checked out Jon's a couple months ago and got to play with my friends in Mexcico.

I wondered if the hud would be intrusive or something I'd grow used to,