Captain Francesco Schettino jumped into a lifeboat and abandoned the Costa Concordia minutes before his cruise liner capsized off the Italian island of Giglio, a court has heard.

Concordia midshipman Stefano Iannelli told a court in Grosseto, Tuscany, that Schettino did not fell from the liner, as the captain and his defence team maintained, but boarded a lifeboat and safely made his way to shore while passengers struggled in the water.

Iannelli said that as the Concordia was being evacuated after it hit a rock he was helping people off the vessel with a rescue team on the fourth deck of the starboard side.

When there were no more passengers in sight, he reached a lifeboat together with Schettino and four other people.

"I jumped on the top of a lifeboat. The captain had jumped moments before me," Iannelli told the court.

"As soon as the launch left, the ship collapsed on its side and the deck where we were was submerged.

"During the journey to reach the shore we recovered some passengers from the water," Iannelli said in answer to a question by prosecutor Stefano Pizza.

Schettino is standing trial on charges of manslaughter, causing a shipwreck and abandoning ship.

Prosecutors alleged the captain, nicknamed "Captain Coward" in the Italian media, steered the liner too close to the island of Giglio because he wanted to perform a sail-past salute. The ship crashed into a reef, took on water and capsized.

He faces up to 20 years in jail. He denies the charges.