After a week of sailing between Thailand's southern islands, you'll be ready to go Gilligan. On G Adventures' new cruise, eight sailors lounge on a 37-foot live-aboard catamaran, drifting between ten limestone islands jutting from the 88-degree water of the Andaman Sea. Like snorkeling? Tell the captain (guests help choose the trip's route) and he'll take you to the mangroves of 98,800-acre Ao Phang-nga National Park in the evening, after the tour boats leave, for a private viewing of the park's 80-plus marine species. Departures from November to April; from $1,250; gadventures.com