Disappearing from the everyday grind into world of underwater adventures, beachside resorts, and tropical dreams sounds like a pipe dream. it's not. Each of these diving adventures, whether near, far, or halfway across the world, comes with its own unique draw and entirely feasible set of essentials (stay, eat, do) for everyone from vets with vacation days to new divers with a long weekend free. Swimming with Caribbean reef sharks in the Bahamas, exploring the Northern Hemisphere's largest barrier reef, or crossing the thermocline boundary to explore ghostly WWII wrecks in Papua New Guinea might sound daunting, but whether you have three days or two weeks, there's time enough for one of these adventures.