Fathom vs. KISS Classic?

[Blackfrogfeet]

Hey scubaboard,

Ive started saving for my first CCR, and have been doing the necessary research to figure out what unit I want. I'm mainly interested in backmount manual CCRs with backmounted counterlungs, that are fairly modular and can accept a wide variety of cylinders in case I want to dive with a backmounted DIL config.

I've started to narrow it down between the Fathom and the KISS, leaning more towards the Fathom as it comes ready to accept off board DIL put of the box, and it seems the KISS does not. Does anyone have experience with both units?

I will be doing primarily deep ocean technical dives in cold water and dabbling in caves a few times a year.

 

[rjack321]

Its super easy to offboard dil on a classic. It is not so easy to backmount large dil bottles on a classic.

I dive with a fathom needle valve (on my mCCR) and compared to the kiss mav it is far bulkier and can be somewhat challenging to adjust with dry gloves on. The kiss MAV is nice but I do worry about the orifice clogging.

I have an opinion but first, what is "deep"? 50m, 60m, 80m, 120m??

 

[Blackfrogfeet]

Its super easy to offboard dil on a classic. It is not so easy to backmount large dil bottles on a classic.

I dive with a fathom needle valve (on my mCCR) and compared to the kiss mav it is far bulkier and can be somewhat challenging to adjust with dry gloves on. The kiss MAV is nice but I do worry about the orifice clogging.

I have an opinion but first, what is "deep"? 50m, 60m, 80m, 120m??

Right, what is deep... I want to be diving in the 50-60m+ ranges at the drop of a hat (yes I know not deep for some) and have the ability to go to the 75m range when the dive warrants it.

 

[rjack321]

Right, what is deep... I want to be diving in the 50-60m+ ranges at the drop of a hat (yes I know not deep for some) and have the ability to go to the 75m range when the dive warrants it.

I was just asking because the orifice on the Classic bumps into the IP around 85m. You can get smaller orifices or switch to a needle valve which isn't rocket science but still.

Overall the Fathom is much better built (the cell kidney on the classic works - but could be much better, the classic also has relatively poor water traps and a few other weak spots even if its functional) although for your planned dives the Fathom scrubber is monsterous and depending on how often you get out you may waste a bunch of sorb. You many want to ask about getting a smaller 5 or 6lb scrubber and a spacer. You could always have big and small scrubbers.

Backmounting your dil/bo ok, its heavy as heck though. And you are often stuck with the "wrong" BO for the dive unless you have multiple sets of tanks.

I'm curious why you decided you wanted an mCCR vs the JJ?

 

[kensuf]

I've been deliberately not weighing in because of my bias (I'm a Fathom instructor). I've got over 300 hours on both units and by far I believe the Fathom to be a superior unit.

1. Easier to maintain/clean? Fathom.
2. HUD by default? Fathom.
3. Better work of breathing? Fathom (the KC axial scrubber can make WOB poor if using 797/812 mesh).
4. Water tolerance? Fathom.
5. Scrubber options? Fathom (I normally use the 5.5# scrubber, but it's nice to have the big boy scrubber if I need it).

I have a soft sport for the Classic, it was my first rebreather and I did some cool diving on it, but the Fathom is superior.

 

[Blackfrogfeet]

I was just asking because the orifice on the Classic bumps into the IP around 85m. You can get smaller orifices or switch to a needle valve which isn't rocket science but still.

Overall the Fathom is much better built (the cell kidney on the classic works - but could be much better, the classic also has relatively poor water traps and a few other weak spots even if its functional) although for your planned dives the Fathom scrubber is monsterous and depending on how often you get out you may waste a bunch of sorb. You many want to ask about getting a smaller 5 or 6lb scrubber and a spacer. You could always have big and small scrubbers.

Backmounting your dil/bo ok, its heavy as heck though. And you are often stuck with the "wrong" BO for the dive unless you have multiple sets of tanks.

I'm curious why you decided you wanted an mCCR vs the JJ?

Yeah for the scrubber I would definitely get the 5.5lb for it, and I'll look into a spacer too. That's a good idea. I'm diving in 8-9 degree Celsius water, so 3hr dives just aren't happening for me. 2hr max.

I'm not dead set on back mounting my Dil, but I would like it to be an option. The conventional config on the Fathom also appeals to me for the light weight because I do a lot of shore dives with sketchy entrances.

The main reason I'm not going JJ and I'm looking at the Fathom is because it's 15lb lighter out of the box and a lot smaller than a JJ, but if I want to dive it in a "GUE config" in order to operate with a lot of my GUE dive buddies I do so. I can also just stick with the conventional config for the Fathom which looks nice to me.

 

[rjack321]

Yeah for the scrubber I would definitely get the 5.5lb for it, and I'll look into a spacer too. That's a good idea. I'm diving in 8-9 degree Celsius water, so 3hr dives just aren't happening for me. 2hr max.

I'm not dead set on back mounting my Dil, but I would like it to be an option. The conventional config on the Fathom also appeals to me for the light weight because I do a lot of shore dives with sketchy entrances.

The main reason I'm not going JJ and I'm looking at the Fathom is because it's 15lb lighter out of the box and a lot smaller than a JJ, but if I want to dive it in a "GUE config" in order to operate with a lot of my GUE dive buddies I do so. I can also just stick with the conventional config for the Fathom which looks nice to me.

If I can I do 3+hrs in 4C you can do 3 or even 4hrs in 8C. Wet Dream up by Zeballos is usually about 8C and doing more than 2 hrs there is actually pretty comfy. Suit heat is a good idea but its not that brutal.

I'm not really a fan of the combined dil/BO when you might do a 30m dive on saturday and a 70m dive sunday (or vice versa). Plus they are a pain to top off.

Sidemounting 2x al80s as BO only and using a long hose on the deeper BO is pretty normal in the (non-GUE) CCR community and there is zero evidence its more or less safe the backmounted 50s. Hopefully you can work with your existing buddies so that you can use what makes the most sense. Happy to dive with you either way once the border reopens.

I like the Fathom, just temper your needle valve ra ras lol. It's not a miracle device, especially with dry gloves. (Mine is on my Kiss sidewinder).

 

[rddvet]

Yeah for the scrubber I would definitely get the 5.5lb for it, and I'll look into a spacer too. That's a good idea. I'm diving in 8-9 degree Celsius water, so 3hr dives just aren't happening for me. 2hr max.

I'm not dead set on back mounting my Dil, but I would like it to be an option. The conventional config on the Fathom also appeals to me for the light weight because I do a lot of shore dives with sketchy entrances.

The main reason I'm not going JJ and I'm looking at the Fathom is because it's 15lb lighter out of the box and a lot smaller than a JJ, but if I want to dive it in a "GUE config" in order to operate with a lot of my GUE dive buddies I do so. I can also just stick with the conventional config for the Fathom which looks nice to me.

when you buy the fathom you have the option of the 5.5 scrubber with spacer or the 9lb scrubber.
The fathom is hard to beat for travel. I can fit the entire thing minus bp into a carry on and also throw my can light and computers in there. My wife is now diving the fathom in gue configuration and loves it. I still dive sm bailout. The JJ was the other unit I considered but I prefer mccr and the JJ is heavy as hell.
I’m pretty biased to the fathom since it’s my first unit. IMO the kiss and the fathom can’t be compared. I took the sidewinder course and found the quality of the kiss unit to be surprisingly cheap and crappy. I’ve played around with a classic and it’s no different. The fathom is much more robust, well fabricated, and is more modular than the kiss. I don’t believe you can dive the kiss with inboard 50s.
i would say jump on the fathom and don’t think twice. Charlie’s customer service is up there with shearwater, underwater light dude, dgx, and dris

 

[tbone1004]

@rddvet you can dive the classic with onboard dil. It's not the most glamorous solution though. You would just swap out whatever bottles those are for the bigger bottles and call it a day. I do recommend going with the Fathom though

 

[ginti]

My wife is now diving the fathom in gue configuration and loves it. I still dive sm bailout. The JJ was the other unit I considered but I prefer mccr and the JJ is heavy as hell.

Just curious here

I thought GUE had only JJ and RB80... what is a fathom in gue config? could you provide more info, even in private if you prefer?