The Friday File: The biggest cruise ship, the Symphony of the Seas (2018) with gross tonnage of 228,081 and a maximum capacity of 6,680 people. The next largest, the Harmony of the Seas (2016) with gross tonnage of 226,963 and with a capacity of 6,687. In third, Oasis of the Seas at 226,838 but with a record capacity of 6,780! The biggest supertanker built (now scrapped), the Bellamya at 275,276.