USS Vandenburg

Though only sunk in 2009, the Vandy is already a main attraction for both divers and sea life frequenting the waters off Key West. The world's second-longest artifical reef, the 523-foot-long ship lies 140 feet deep, though its main deck is about 90 feet under the surface. While navigating the schools of yellowtail snapper, keep an eye out for bait balls, arrow crabs, nascent coral -- and the Conch Republic flag.