Fathom CCR vs JJ-CCR

[Madddogggy]

Hi All,

Interested in hearing from those that is willing to discuss their experience with both units. Prefer to hear from those with more than try-dive experience.

Also, has the Fathom gone through any 3rd-party testing?

Thank you,

 

[tbone1004]

there's a lot of differences between the two, but the one with the most experience is probably Jon Bernot at cave country dive shop who is an instructor on both units.
No 3rd party testing on the Fathom but since the important bits are stock standard parts, I frankly don't see the reason for it unless they try to sell to Europe. They're two wildly different units though so I'm curious how you landed on these two

 

[kensuf]

I've got a little bit of experience with the Fathom and have stayed in a Holiday Inn Express. What are you looking to hear about?

 

[tbone1004]

I've got a little bit of experience with the Fathom and have stayed in a Holiday Inn Express. What are you looking to hear about?

I thought you were higher class than HIX!

 

[JohnnyC]

Are there specific differences that you're interested in? They're significantly different units in terms of their method of operation and their operating principle.

 

[Madddogggy]

I have done try dives on both. Understand the main differences, just looking for the nuances/devil in the details that I may have missed with not having more than try dive experience on either unit.

 

[JohnnyC]

I have done try dives on both. Understand the main differences, just looking for the nuances/devil in the details that I may have missed with not having more than try dive experience on either unit.

They're fundamentally different units. There's no "nuance" between them, they operate in a completely different manner, and something like the weight of the loop hoses or what mouthpiece each unit comes with is so far down the list compared to the BIG differences.

It's like asking for the nuances between a RAM 3500 Cummins Turbo Diesel and a Corolla Hatchback. Uh, the headlights are different?

 

[rjack321]

They're fundamentally different units. There's no "nuance" between them, they operate in a completely different manner, and something like the weight of the loop hoses or what mouthpiece each unit comes with is so far down the list compared to the BIG differences.

It's like asking for the nuances between a RAM 3500 Cummins Turbo Diesel and a Corolla Hatchback. Uh, the headlights are different?

well they ARE both backmount units
and they both have backmounted CLs
and ummmm that's all I got

 

[tbone1004]

seconding what @JohnnyC said. They're both backmount rebreathers, that's about where the similarities end. The Fathom is essentially a manual Meg with an ATS unilung and needle valve, but the JJ is a completely different beast. I don't know if Johnny's analogy is quite so accurate, but I think it's more like a 12v Cummins dually vs a modern Duramax 2500. Both pickup trucks, both diesel, but too many differences to bother looking at the nuances between the two since the nuances shouldn't make that decision. You can put a needle valve on a JJ, you can put a unilung on a JJ, you can put a full JJ loop on a Fathom if you were so inclined, you can use the same mav's on both units. The question if you're looking at those two is largely going to come down to priority for a solenoid vs. scrubber capacity.

 

[Madddogggy]

My apologies, was posting this thread between meetings and probably should have labeled this thread differently.

Maintenance issues and/or components one should be aware of? Particular mechanical failure points.

Able to dive the stock in a wetsuit? If not, what mods did you have to make? Tanks/Backplate/Fins, etc

Were trim weights need to get the unit to trim out? My very-limited experience with the JJ would say yes to this, but looking for more experience user to weigh in. The Fathom trimmed out nicely and very little effort to remain in trim.

Experience with diving the Fathom in water <=5C (41F): How did the unit perform?