Originally Posted by JayTeeMe
Somehow you have to get rid of CO2 though. I'm not sure how you'd do this without breathing.
I assume he was joking; if not, he was wrong.
Though in fact traditional open-circuit scuba is outdated already, because of rebreathers: A few thousand dollars gets you a scrubber/rebreather setup that uses a small bottle of straight oxygen and can last for ~20 hours underwater.