With your recent posts on the Fathom, I thought I would bump this thread as a JJ diver.
To give you some things to say, "Yes, but..." here are some thoughts ...
Looking at your reply above,
1) why is O2 Injection on the inhale side a bad thing? As I ponder the horrific stuff, there's ascent with a hypoxic mix, and loss of consciousness within a couple of breaths, which could potentially be alleviated by a rapid increase in pO2, better injected on the inhale side. But forethought would also alleviate the problem. Conversely, there's inadvertent O2 spiking, which is far more common, yet less immediately fatal, and lessened by injection on the exhale side;
2) the stand isn't really very heavy, yet is a bit bulky when trying to pack into a Pelican case. A bit of disassembly is required. As a result, I ponder the Choptima for a bucket list trip to Chuuk. But I like the JJ for my arthritic shoulders, because the valves are down;
3) no standard BOV, but I'm contemplating one. Easy enough to add; just not standard;
4) yes, radial scrubber available.
So, I conclude it's just heavier. Maybe a lot. But the Choptima is portable and the front-mounted CL with positive static lung load, vs mCCR as a better design, is a bit of a question for deep dives.
Why would you choose Fathom over both JJ and Choptima? (Except for the JJ head down issue, which I'm working to eliminate with a shoulder coil stent for the inhale CL)
