Blind Descent: The Quest to Discover the Deepest Place on Earth - James M. Tabor Hard to compete with Jason's review, so go read that one at He's dead on about everything, especially the photographs which are astounding.

I remain astonished at the things people will do. This has to be far worse than climbing mountains, because you are basically doing exactly the same thing except it's in the dark and once you have achieved your goal going down you have to survive coming back up.

A quote to whet your appetite: Needing to relieve himself one night, Broad crept to the platform’s edge and let fly into the stream below. To conserve carbide and batteries, he left his lights off and edged cautiously back to his hammock in the dark. Thinking he had arrived, he sat down, but his dead reckoning was off. The hammock spun and tossed him out. His head smashed into the cave’s jagged wall. Stunned, flailing, he fell off the platform. In a move straight out of an Indiana Jones movie, he managed to grab one of the ropes on which the portaledge hung from the cave wall. Dangling there in the dark by one arm over the water ten feet below, Broad screamed for help, but the waterfall’s roar drowned out his cries. With his grip loosening, Broad realized that he would have to save himself, and quickly, or fall and be swept away into the void. He began swinging back and forth, waving his free hand around in the dark, and by sheer chance grabbed one of the other ropes from which the platform hung. With the last of his strength Broad dragged himself back up and flopped onto his belly, gasping and shaking, dizzy with pain, stunned by the fact that he had almost died in this supercave, not from diving but from falling out of bed.