Cat Island has a continental shelf in the north, with a wild, untamed shoreline that offers some of the best scuba diving anywhere in the world. There are walls with a 100-200-foot drop-off and features like giant sponges and black coral bushes. You can dive a blue hole descending 80-100 feet; “The Tunnels,” a coral garden with crevices, canyons and fissures at 30 feet; or Naked Point with numerous stone crabs and small corals. The reefs off its south shore are virtually unexplored, home to species like grouper, tarpon, trigger and trumpet fish, sponges, gorgonians, Elkhorn, lettuce and brain corals, plus expanses of sea fans. An old shipwreck lies half submerged and a Spanish battleship sunk in 1898 is at 20-30 feet. While veteran divers may know their way around the ocean floor, diving lessons and guides are available from a PADI dive center to help novices experience life under the sea.