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I will let you know. I'm the same as you that I had looked into them years ago and they were very expensive.

So, I finally couldn't resist and took a peek... Found this:

https://www.diverightinscuba.com/rebreather-c-330.html

Apparently these are off-the-shelf commercial products these days, priced within the realm that "mere mortals" could afford if serious about things. :)

Here's another one: https://poseidon.com/products/rebreathers

The silent, bubble-free aspect is *really appealing...

And then this: https://www.apdiving.com/en/rebreathers/new-to-ccr/

Wow! Now I can't wait for BEOS to moon, I think I'll need one of these... :D

Lol, I don't think the price has changed all these years! Agreed that it's really appealing :) but I'll stick to my snorkel gear I brought! Thanks for checking into it and the links!!