When it launched in 2010, Norwegian Epic was hailed as the ship that would set the agenda for 21st-century cruising. In some ways, it did: Many of the amenities — extravagant water slides and a large sports complex, cutting-edge entertainment, 20 food venues, and a cabin complex designed for solo travelers — have appeared on Norwegian Cruise Line's subsequent ships. And some of the concepts have been "borrowed" by other lines as well.