Whale and hammerhead sharks. The Blue Hole. The second-longest barrier reef in the world. Five hundred species of fish. These are just some of the reasons that divers flock to Central America. Make a trip to any of these places — the cayes and atolls of Belize, the Bay Islands of Honduras and Costa Rica's Cocos Island, for starters — and you'll see why this diving is among the best in the world.