Kurson provides one of the best narratives about SCUBA diving, and high risk shipwreck exploration, that I’ve ever come across.  I love his description of navigating a wreck:

“A diver who enters a wreck…must conceive of space differently than he does on land…He must remember everything – every twist, turn, rise, and fall – and he must do so in an environment of few obvious landmarks and where most everything is sweatered in sea anemones.