France: Giant Symphony of the Seas cruise ship nears completion Symphony of the Seas, the soon-to-be world's largest cruise ship, will be delivered to American shipowner Royal Caribbean Cruises on March 23 by STX France shipyard in St. Nazaire. The 1.2 billion euro ship, which measures 362 metres long and 66 metres wide and weighs some 230,000 tonnes, will be able to accommodate around 8,000 passengers.