The boom swings lugubriously, its shadow slicing across the sun-steeped white deck of the Alternate Latitude. Water chuckles against the double hulls of the Voyage 440 ship. In four cabins, air conditioners purr as the boat cuts towards the azure horizon, dwarfing the other catamarans on Galveston Bay.

During chartered sailing trips, Captain Steve—who holds a 50-ton United States Coast Guard Masters License—and his crew steer the vessel as passengers lounge on trampolines on the deck and sip drinks. The ship, which was built in South Africa, now makes occasional cruises to the Virgin Islands. Queen-sized berths in each cabin cradle passengers during overnight trips and after chamomile-tea-drinking contests.