mempilot:
What, if any, are the depth limitations of SC and CC rebreathers? ... OK, that's deep!!
The Megalodon has been taken past 500ft., as has the Cis-Lunar. MK series RBs have been in that neighborhood, too.
Except for the Cis which was rated at that depth, most CCRs are rated for and tested to less. Usually 300fsw, still deeper than you dive currently.
The RB80 SCR has been used deeper than 100 meters (330)ft.
It is the only civilian SCR build for such depth, from gas switch block (same gases as OC, same deco) to scrubber size.
I've got a lot of money tied up in OC. What kind of cost is involved with the equipment and training for CC RB? I'm all about training and experience, and I dive about 2-4 times a week. 1-2 of those are tech.
Electronically controlled CCRs usually fall between $7500 and $8500, with used MK series around $10,000 (depending on condition & electronics) and used MK-5p even higher.
Training for basic certification should be somewhere between $1200 and $1800, depending on the instructor and any deal you may be able to get by purchasing a unit.
The RB80 is the only serious SCR contender (save some knock-offs for which training/certification might not be available), all training is GUE. DIR-F and Tech-1 are required to get RB training, so depending on your current c-cards that may be a long and expensive way to go. The RB itself isn't cheap either, complete with frame and plumbing probably more than the average CCR.
I'm all about training and experience, and I dive about 2-4 times a week. 1-2 of those are tech.
All initial RB training will be for recreational diving, 130 ft. max and no deco.
When going from OC to CC you'll need to start over again, learn to dive whatever you select, become proficient, move up.
When you read reports about CCR accidents and fatalities you'll see that too many of them happened to divers who went past their RB experience. So you'll have to take a break from the weekly tech dives for a while ... .