ABU DHABI // Divers from Abu Dhabi rescued a ship's cook presumed drowned when his tugboat sank but who survived for nearly three days in an air bubble in the vessel 30 metres under the sea.

The rescue mission began when the Jascon-4 with 12 crew on board capsized about 30 kilometres off the coast of Nigeria's oil-producing Delta state.

Divers with the Emirati-owned Mussaffah construction and installation company DCN Global were installing underwater pipelines off the west coast when they responded to the May Day call.

After 62 hours of searching the sunken vessel they had given up hope of finding survivors - when a hand shot out from the dimly lit interior of the vessel and grabbed a diver's arm as he swam past.

"It was incredible. They thought they were just looking for bodies," Jed Chamberlain, 40, a manager at the company, said yesterday.

The cook, Okene Harrison, a Nigerian, had been able to get himself into a small air bubble in a still-intact compartment in the vessel and stayed alive by drinking Coca-Cola.

The drama began early on Sunday, May 26, when the Jascon-4 got into difficulties during a static towing operation.

DCN's divers were on board the Lewek Toucan, a dive-support vessel chartered by the Nigerian offshore engineering company West African Ventures, and were 17 hours from the incident when they heard the May Day call.

"On receiving notification, West African Ventures had no hesitation in instructing DCN to immediately cease operations on the pipeline and respond with the saturation diving team," said Mr Chamberlain, a British expatriate.

"We located the Jascon-4, which lay upside down on the sea bed at 30 metres. At the time, there was no trace of crew members and little hope of finding survivors.

"The divers entered the vessel to retrieve bodies of the crew members. Amazingly, the recovery mission turned into a rescue mission."

Mr Chamberlain said everyone was "amazed and elated" to learn a crew member had been found alive but initial celebrations were short lived as they worked to bring Mr Harrison safely to the surface.

"Because he had been 30 metres underwater his body had filled with nitrogen and we had to put him into a decompression helmet before he could be brought to the surface," said Mr Chamberlain.

If Mr Harrison had been brought up too quickly, the nitrogen in his blood could have caused brain damage or even death. He was kept in a decompression chamber to manage the release of excess nitrogen.

"Amazingly, after two to three days, he was absolutely fine," said Mr Chamberlain.

The bodies of 10 other crew members were recovered during the rescue mission. One is still missing, presumed drowned, and the rescue operation has been ended for safety reasons.

"The vessel has become so unstable that the risk of injury to our rescue divers has become unacceptably high," West African Ventures said.

jbell@thenational.ae

* Additional reporting by Reuters