The reality of the situation for me was a few fold. 1. I had been certified to 500’ since 1998 and hadn’t been there yet. Close but no cigar.
2. Years ago, shortly after the Optima adopted Shearwater electronics, people kept saying that the “Optima wasn’t a great technical rebreather”. It absolutely was then and certainly is now. So after the debut of the CM I started hearing some of those same people say that it wouldn’t work, wouldn’t breathe well, had a narrow mission parameter, I wanted to prove them all wrong. I was one of the first people to get a CM and one of the first instructors on it. So, I took the 17lb package (fully rigged) and flew to Bonaire with it.
And, it breathes just as well at 500’ as it does at 50.
At any rate, back on topic...
I’ve amassed nearly three decades of diving deep. First as a cave diver, then as a commercial diver, then as a CCR diver. I didn’t go into it lightly and I knew my limitations, I knew all the hazards and was comfortable with my ability to mitigate those hazards.
if you can do that, you’ll be fine, probably.