For those that like documentaries, I just watched the first of an excellent new two part BBC documentary that was just on with Dr.Kevin Fong, about the risks of underwater pursuits. He puts himself through several experiments. He talks about how nitrogen dissolved in the blood steam at extreme water pressure (he's put into a compression chamber to simulate it) makes him drunk and disrupts his ability to think and talk. His voice sounds like he's on helium and he develops a lisp. He looks at saturation divers in the north sea who live and work at extreme pressure in tiny capsules for a month, and it takes a week to slowly bring them up to avoid the bends. Also, a fit world class female free diver who has learned to hold her breath for over 5 minutes. Apparently there are world champion females who do over 8 minutes, and men who do over 11 minutes. 
So here's the link, and part 2 next week is all about getting to space.
http://www.bbc.co.uk/iplayer/episode/b0195rlg/To_Boldly_Go_Down/

So here's the link, and part 2 next week is all about getting to space.
http://www.bbc.co.uk/iplayer/episode/b0195rlg/To_Boldly_Go_Down/