Wetpixel.com is a great resource for underwater photography. One of the main contributors, Eric Cheng, is a phenomenal award winning photographer. One of his photos,
"Screaming Turtle", recently made the cover of the Sport Diver magazine's end of year best photography edition. That photograph was also featured as part of an exhibit on animals at the Smithsonian and has even spawned tatoos.
Eric specializes in photographing sharks. Here's a cool 3 MB video of the sharks "playing" with Eric.
Shark Video (From Eric's Site)
To view more of Eric's photographs visit him at www.echeng.com
Live Aboard Diving Trips - www.agressor.com