OK< if I still had heroes left, this guy'd be one of them. He scuba dives 83 feet to the bottom of an Arizona lake, and then drops headfirst down a very tight and restrictive mine shaft, bottoming out at an insane 171 feet under water. Then he swims back into the mine, exploring 800 feet of tunnels over six dives. Mad skillz are involved here (cave diving, deep diving and technical diving skills) plus a boatload of guts. Watch it full screen.
I want to do this. I would kill to do this and other dives like this. Now if only my dive buddy would get over his fixation on safety, I'm thinking that we could top this somewhere.
Who dares, wins.