Roatán

Roatán needs 3 days: diving or snorkeling in the Mesoamerican Reef, the second-largest coral barrier in the world, on one, and the beaches of West Bay and West End for the rest. March-September is best, with calmer waters and optimal visibility. It's inexpensive by Caribbean standards, one of the most accessible diving destinations in the world. It's the largest of the Bay Islands and one of the most award-winning dive spots on the planet, with coral walls dropping steeply just meters from shore and marine biodiversity comparable to much pricier Caribbean destinations.