HARMONY of the Seas, the world’s largest cruise ship, set off Thursday on its first sea trial from Saint-Nazaire, western France, with just two months to go to delivery.

    The city’s STX France shipyards began building the 1-billion-euro (US$1.1-billion) mammoth for U.S. shipbuilder Royal Caribbean International (RCI) in September 2013.

    Thousands of people gathered at the dock to watch as the 120,000-ton ship was helped out to sea by six tugs.

    Some 500 people, mostly crew as well as officials from the owners and engineers and suppliers, were on board for the first trial, which continued until yesterday.

    The ship, with a height of 70 meters, has been an imposing presence in Saint-Nazaire, visible from miles away.

    For months, tourists have been allowed on board to gape at the innards of the ship that has 16 decks and stretches 362 meters, 50 meters longer than the height of the Eiffel Tower.

    Three pilots who have trained on a simulator in nearby Nantes for the past year, helped the captain in the tricky maneuvers needed to guide the hulking ship out of the Saint-Nazaire estuary.

    The tugs first helped the ship back out of its berth before turning it around and then guiding it out to the open sea.

    The pilots will leave the vessel once it is 20 kilometers out at sea.

    Such is the scale of the Royal Caribbean International ship, when its first 6,000 passengers board in Southampton in May they will be issued with GPS-style wrist trackers so they won’t get lost in her labyrinthine interiors.

    And a squad of “Royal Genie” butlers will be at the beck and call of VIP guests. Thrill seekers will be able to choose from four onboard slides, including the Ultimate Abyss, the world’s tallest slide at sea, boasting an impressive 30-meter plunge.

    Elsewhere, a zipwire will whizz adventurous guests nine decks above the open-air atrium, robots will pour cocktails at a “bionic bar,” and passengers can learn to surf on a ship-board wave simulator.

    Entertainment includes Broadway’s hit musical, Grease in the full-size theater, a state-of the-art multimedia ice rink spectacular and high-flying acrobatics.

    The ship has 16 restaurants and cafes — including a Jamie’s Italian — boutique shopping on the Royal Promenade, and high-speed Wi-Fi in the staterooms. And for voyagers wanting a challenge, there’s the Escape Room where guests have to try to break out by solving a series of puzzles.

    Vast and full of surprises, Harmony Of The Seas is like something from the imagination of Jules Verne.

    Some 2,000 crew are to cater for the needs of more than 6,000 passengers on Harmony, which is a meter wider than the current twin ocean-going monsters of the pleasure cruise world, the RCI-owned Allure of the Seas and the Oasis of the Seas, which are also 362 meters long.(SD-Agencies)