Off the southwestern stretch of Antigua, Cades Reef is best for experienced snorkelers. There is no island or beach here. Rather, it’s an open-ocean site where day boats moor up along the 3-mile long barrier reef. Here, you’ll find healthy elk horn coral, a rare species whose reddish tan branches resemble, well, antlers. Flitting among the corals are schools of bright blue Creole wrasse, yellow French grunts, black durgon fish and dozens of other species.