How long can you hold your breath underwater? Me? A minute, tops!
Well, however long you can hold your breath, I betcha it's nothing when compared to what Gianluca Genoni just did: he set a new world record for breath-holding, handily beating what David Blaine did (7 minutes) and the previous world record:
Gianluca Genoni held his breath for 18 minutes 3.69 seconds while lying underwater in a Mantua swimming pool, beating German diver Tom Sietas, who managed 17 minutes 19 seconds in September - also on live TV - to unseat Blaine from the Guinness world record book.
http://www.ansa.it/site/notizie/awnplus/english/news/2008-11-26_126282670.html - via Underwater Times
21 minutes is unbalievabol
I went to school with a guy named Nach, btw. :)