Finnish shipbuilders say the world's largest cruise liner has been launched into water for the first time.

Royal Caribbean's Oasis of the Seas will be completed within a year before sailing to Miami. The ship was floated out Friday at a Turku shipyard dry dock.

It has 16 passenger decks with 2,700 cabins and can accommodate 6,300 passengers and 3,000 crew. It is 1,200 feet long and has an open-air arena the size of a football field.

Special features include a 750-seat theater modeled on an ancient Greek amphitheater, a skating rink and a youth area.

The 225,000-ton vessel has a price tag of $2.5 billion. Royal Caribbean International has ordered another Oasis class liner due to be launched in 2010.