A VIETNAMESE seaman survived five days floating in open ocean with only a life jacket for protection.

The sailor's perilous situation occurred after his cargo ship sank killing all his 22 crew mates.

Vietnam's state shipping firm said the Vinalines Queen, which disappeared on Christmas Day after passing the island of Luzon in the Philippines, had capsized, apparently without sending a distress signal.

The country's government website said the single surviving sailor, Dau Ngoc Hung, was found in open water by the British ship London Courage yesterday morning, almost a week after his own vessel went down in violent seas.

Nguyen Anh Vu, director of the Vietnam Maritime Rescue Cooperation Centre said Mr Hung had reported that "the vessel sank very quickly ... after being strongly overturned to the left" in the early hours of Sunday morning.

Mr Hung, 31, was picked up around 350 kilometres away from the site of the accident, Mr Vu said on the government site, adding that the rescue vest had saved the sailor's life. The British ship is now on its way to Singapore.

Mr Vu said that the Vinalines Queen had gone down in very bad weather in waters up to 5,000 metres deep.

"According to our initial information, only one sailor has been rescued and the vessel has not been found yet," an official at Hanoi-based Vinalines said, asking not to be named.

Vinalines said its ship was carrying more than 54,000 tonnes of nickel ore and was travelling from Indonesia to China when it lost contact.

Vietnam had appealed to the Philippine, Taiwanese and Japanese coastguards for help in finding the vessel, but had heard nothing of the ship until now.

"We are now focusing our efforts on searching for the Vinalines Queen," the company official added.

The Japanese-built 190 metre Vinalines Queen was one of the largest and most modern cargo ships in the Vietnamese fleet, with a capacity of more than 56,000 tonnes. It had been in service for Vinalines since 2005.

Rescue experts quoted in the Vietnamese press said emergency equipment on the vessel should have automatically sent SOS signals to satellites and coastal rescue stations. It is not yet clear why no distress message was transmitted.

Vietnam National Shipping Lines, or Vinalines, is one of the communist country's main state-owned enterprises.

Global shipowners association Intercargo issued a statement in December 2010 warning of the hazards of transporting nickel ore which, it said, may liquefy and cause a ship to list if not loaded to international standards.

The body said it was "completely unacceptable" that three cargo ships, all carrying nickel ore and all loaded in Indonesia, had sunk in 2010, killing 44 seamen.

