Best known for its trio of ships with sails, Windstar Cruises doubled its fleet with the purchase of three small ships from Seabourn it calls “power yachts.” Now, the line offers itineraries around the world. The ships accommodate anywhere from 148 to 310 passengers, and the atmosphere is upscale but relaxed, with an emphasis on service. Sure, the new vessels don't have sails to catch the wind, but they're still intimate spaces.