The ship boasts shops, restaurants and bars on a man-made "street"
One of the world's largest cruise ships is to be based year-round in Southampton in a move thought to be worth millions to the local economy.
The 4,300-passenger Independence of the Seas was launched in 2007 and has been using the port for its summer sailings.
The Hampshire port will become the Royal Caribbean International ship's home from April 2010.
Councillor Sarah Bogle welcomed the news and said it was crucial the port kept attracting the biggest ships.
"This is obvious great news for the port and the city as it is a very prestigious cruise ship," the council's shadow member for economy said.
Dwarf Canary Wharf
"It is estimated each ship brings about £1m into the local economy every time it comes into port - and we already have about 250 of these occasions in a year.
"The cruise business is an important part of the image of the city and helps sell Southampton and attract investment."
Standing upright on its bow, the £400m ship would dwarf the UK's tallest building London's One Canada Square at Canary Wharf which is 771ft tall (235m).
The ship, longer than three-and-a-half football pitches, boasts shops, restaurants and bars on a man-made "street" which is longer than the pitch at the new Wembley Stadium.
Robin Shaw, Royal Caribbean's UK and Ireland vide president and managing director, said: "It means that we firmly cement our position as one of the leading players in the UK cruise industry.
"When Independence of the Seas first sailed from the UK it was one of the best-performing ships in the fleet.
"We are committed to continuing to grow our presence in the British and Irish markets."