If you're referring to Giancarlo Bellingrath's 12:47 (or previous record Gianluca Genoni 12:34), that was done on pure o2, so it's kind of pointless (and has since been beaten by for example Bill Strömberg, 13:05).
If this was done without pure o2, then I'd be really interested in details (and propably not alone).
12 minutes without pure o2 sounds like something within the realm of possibility. All it would take is a genetical crossing of Tom Sietas and Hubert Maier I imagine (yeah yeah, don't even go there...I'm not suggesting they actually try it. And if they did, then I would NOT be interested in details
. But it would be an absolute sensation in the freediving world and I remain sceptical.
