Shawn, There are no tropical Islands in the continental United States. To be a true Tropical Island, one must go to the Tropics. there are a few Islands which are United States territory, but they are either inhabited or U.S. military installations. A tropical island sounds idyllic, but the obstacles to survival can be even tougher than the Arctic, ie no water, periodic Typhoons that inundate the entire landbase and lovely diseases like Malaria, Dengue, yellow to name a few.