Italian engineers have started an operation to refloat the Costa Concordia in preparations for the wreck to be towed away for scrap.
The once luxurious 290-metre long cruise ship, now covered with rust, has been raised approximately two metres from the platform on which it has been resting since it was first lifted from the seabed about a year ago.
To lift the shipwreck, the engineers pumped air into 30 large metal boxes, or sponsons, attached around the hull of the 114,500 tonne ship. The air forced out the water in the sponsons, lifting the vessel off the underwater platform.
The ship will be further stabilised with chains and cables before tug boats move it about 30 metres into the harbour, where it will be prepared to be towed within days to Genoa in northern Italy, to be scrapped.
"The boat is now floating with its sponsons attached," said Franco Porcellacchia, the engineer in charge of the salvage.
"The ship is upright and is not listing either longitudinally or latitudinally. This is extremely positive," he told a news conference six hours after the operation began.
The ship, which had sunk about two and a half years ago near the Italian island of Giglio killing 32 people, was lifted from the seabed about a year ago in what has become one of the largest naval salvage operations in history.
The ship's captain, Francesco Schettino, is on trial accused of manslaughter, causing a shipwreck as he sailed too close to shore to "salute" the port, and abandoning ship. He is fighting the charges.
Paying for the disaster, including breaking up the vessel and repairing the damage to Giglio, is likely to cost the ship's owner and operator Costa Crociere, a unit of Carnival, more than €1.5bn (£1.19bn), its chief executive said last week.
The hulk will be demolished and scrapped in Genoa by a consortium including oil services company Saipem and Genoa-based companies Mariotti and San Giorgio.
Costa Concordia salvage infographic