It's fitting that the largest ship in the world has one of Broadway’s biggest hits on board. Harmony of the Seas is showing “Grease,” in an adaptation by the team at Royal Caribbean that blends together the movie and the stage show. The high-energy cast, imaginative costumes, and intricate set and props (there's a full-size car on stage!) of the sing-along-friendly production also bring it to a level not usually seen in cruise ship theaters. Watch our video above to hear more about this hot new show.