The headline aqua show on Royal Caribbean's Symphony of the Seas is titled "HiRO." Performed in the ship's iconic AquaTheater—an open-air amphitheater at the stern featuring the deepest pool at sea—HiRO is a high-octane spectacle that combines extreme athletics, high-diving, and synchronized swimming with cutting-edge technology. The show features world-class divers who plunge from 10-meter platforms, aerialists who perform complex maneuvers high above the audience, and dancers who utilize the pool's shifting floor depths to create "water-borne" choreography. The production is known for its intense energy and cinematic lighting effects, pushing the boundaries of what is possible for live entertainment on a moving vessel. Because of the show's popularity, guests are highly encouraged to book their seats via the Royal Caribbean app as soon as they board, as the limited-capacity seating in the AquaTheater often fills up quickly for both the evening and late-night performances throughout the voyage.