Spectrum of the Seas boasts a gross tonnage of 169,379 GT; a length of 1,139 feet; and 18 separate decks, with 16 accessible to passengers. At maximum capacity, the ship holds 4,905 passengers, but on a normal sailing with double occupancy, it holds 4,246 passengers. Symphony of the Seas, meanwhile, comes in with a gross tonnage of 228,081 GT; a length of 1,184 feet; and 18 decks. At maximum capacity, the ship holds 6,680 passengers, though it normally holds 5,518 passengers at double occupancy, along with 2,200 crew members. So, while Spectrum of the Seas is the fifth-largest ship in Royal Caribbean’s fleet, Symphony of the Seas is the largest and — in fact — Symphony of the Seas is the largest cruise ship in the world currently.