Royal Caribbean International’s twin cruise liners, Star of the Seas and Icon of the Seas, share the title of the world’s largest cruise ship . At almost a quarter of a mile in length, and with capacity for some 5,600 passengers each, these massive vessels are true ocean giants. But put together, Royal Caribbean’s dual flagships would still be only half the length of a new “floating city” that’s currently in the planning stage. The £12bn Freedom Ship is set to have capacity for around 80,000