Bahamas
I have only been to Nassau on Providence. But there are many other island to explore, some only by accessible by boat. A liveaboard trip would be highly recommendable. Water temps were 81 in July and i have seen higher in September where you don't need any cumbersome wet suits to wear. A rash shirt or skin is sufficient. Any type of mm wetsuit is overkill. Visibility is Ok, in the 50ft range with some green algae clouds it seems, so the deep blue water is probably better away from all the development. The island has seemingly an abundance of reef sharks and a shark feeding dive will offer pictures of a life time. But, there are turtles and a big diversity of fish to be seen. Stuart Coves is the number one dive outfit on the island. They have top of the line dive boats, are well organized, offer pick up service, have a fully stocked dive shop and professional crew. But they are a big company. Bahama Divers is smaller and more personal and also offers pick up service. There was some wave action off Paradise Island. The Bahamas are exposed to weather from the north and storm that bear down the east coast of the US can and will affect the Bahamas at certain times. There is some good shopping in Nassau, great restaurants, plus the Fish Fry market near town has restaurants offering a wide variety of conch dishes ranging from burgers to salads. Beaches are beautiful offering plenty of picture opportunities.