The leeward Kona Coast off the Big Island has some of the best diving on Earth. The coral there is not terribly interesting or profuse -- its a relatively new island and so the formations have not gotten a chance to build up yet. The diversity of critters, however, is spectacular. All sorts of rays (including giant Manta Rays), turtles, spinner dolphins, and loads of pelagic and near-shore species of fish all cruise around with wild abandon. The reason for this incredible diversity is that the water depth drops from several hundred to several thousand feet less than a mile off-shore. So the feeding opportunities for big guys coming in from the depths to eat small guys on the lam are quite prolific. Witness this gorgeous shot of a spotted eagle ray in glorious subsea flight.

—Alex, 09/05/06