Fifteen months from now, a cruise ship is scheduled to depart from Miami and travel around the world not in 180 days, but in 274. The nine-month Ultimate World Cruise is billed as the longest world cruise in history, and it will take place aboard Royal Caribbean International’s 962-foot Serenade of the Seas, visiting all seven continents and hitting over 150 destinations in more than 60 countries. Deep inside the ship’s belly, powering it throughout its voyage, will be GE technology.