TOKYO, JAPAN: A Japanese sailor who fell overboard without a life jacket survived a night at sea clinging to an empty plastic bottle he found drifting by, the coast guard said Thursday (October 4th).

Tsuyoshi Kurosawa, a 28-year-old crewman on the 2,997-ton tanker Sakura Maru, was lost at sea for 10 hours after he fell in the sea late Tuesday (October 2nd) while relieving himself over the side of the vessel.

"As an empty plastic bottle was floating by, he used it as buoyancy until he was found," the coast guard said in a statement.

A fishing boat spotted him around 20 kilometres off the coast of the northern city of Kamaishi.

He was hanging on to the bottle with one hand and waving the other, the coast guard said.

He sustained no injuries but will be hospitalised for two to three days due to his low body temperature.

"He was very lucky as the bottle happened to be there," a coastguard spokesman said, adding the bottle was no bigger than three litres.

Water temperatures were also higher than usual at around 18-19 degrees Celsius at the time of the accident, he said.