The operation to refloat the Costa Concordia, the gigantic cruise ship that foundered last year off the Italian island of Giglio killing 32 people, is proceeding smoothly and with "precision," project officials said Monday.

Everything is going perfectly and the project team has gotten through one of the "most uncertain" phases of the operation, removing the vessel from the reef where it had lain for months, Sergio Girotto said.

"The first two hours were the most uncertain because it wasn't known with precision how much the boat was aground," said Girotto, who confirmed that one part of the ship's hull was still being supported on the rocks and another part was being supported on one of the platforms that had been built at the site for that purpose.

This is the first time that engineers are facing a challenge of this magnitude due to the great weight of the cruise ship and its position.

The "parbuckling," the technical term for the operation to rotate the vessel 65 degrees so that it is once again in a vertical position, began at 9 a.m. on Monday and will last about 12 hours.

The story attracted more than 500 reporters from all over the world, who are following the operation to remove the ship - which weighs 44,600 tons, is 290 meters (951 feet) long and about 70 meters (230 feet) high - from the rocks and refloat it.

The president of the Environmental Observatory, Maria Sargentini, also said that no issues of concern had been detected during this first phase.

Before beginning the operation some doubts had existed about the possible environmental impact it would have, given the certainty that much residue and various liquids that have accumulated inside the vessel over the months that it has been aground will spill into the sea as it is brought upright. EFE