The rescue took place in May this year but the video only surfaced this week.

JOHANNESBURG - Remarkable footage of the rescue of a Nigerian tugboat crew member trapped in a vessel for more than two-and-a-half days has gone viral.

The rescue took place in May this year but the video only surfaced this week.

A team of South African rescue divers expected to only find dead bodies in the boat, which had sunk to a depth of around 30 metres in the Atlantic Ocean, about 30 kilometers off the Nigerian coast.

But 29-year-old Harrison Okene, a cook on the vessel, managed to survive for around 63 hours by breathing inside a small pocket of air trapped in a cabin of the boat.

The footage shows divers exploring the sunken vessel when a hand suddenly appears.

One of the men can be heard saying, "We found one," presuming he had stumbled upon another corpse.

But the hand then reaches out and grabs the arm of one of the divers who shouts, "He's alive! He's alive!"

Harrison Okene's hand emerges from the darkness of the sunken tugboat as rescuers scour the vessel for bodies. Picture: Screenshot from AP/Youtube footage.

The rescuer is instructed to reassure Okene by patting him on the shoulder, before surfacing within the air pocket to assess the situation.

Okene is told to drink from a bottle of fresh water before the diver introduces himself and asks Okene his name.

They then prepare him for his escape, and congratulate him. "Good job my friend, well done. You're a survivor!"

This footage of the dramatic rescue only surfaced this week. Credit: AP/Youtube.

SOLE SURVIVOR

Of the 12 people on board, he was the only survivor after the boat capsized on 26 May due to heavy swells while stabilising an oil tanker filling up at a platform.

Reuters reported on the rescue in June, when Okene described the ordeal.

"I was there in the water in total darkness just thinking it's the end. I kept thinking the water was going to fill up the room but it did not," Okene said. Parts of his skin peeled away after days soaking in the salt water.

"I was so hungry but mostly so, so thirsty. The salt water took the skin off my tongue," he said. Seawater got into his mouth but he had nothing to eat or drink throughout his ordeal.

At 4:50 am on 26 May, Okene says, he was in the toilet when he realised the tugboat was beginning to turn over. As water rushed in and the boat flipped, he forced open the metal door.

"As I was coming out of the toilet it was pitch black so we were trying to link our way out to the water tidal (exit hatch)," Okene told Reuters in his home town of Warri, a city in Nigeria's oil-producing Niger Delta.

"Three guys were in front of me and suddenly water rushed in full force. I saw the first one, the second one, the third one just washed away. I knew these guys were dead."

Okene, wearing only his underpants, survived around a day in the four foot square toilet, holding onto the overturned washbasin to keep his head out of the water.

He built up the courage to open the door and swim into the officer's bedroom and began pulling off the wall panelling to use as a tiny raft to lift himself out of the freezing water.

He sensed he was not alone in the darkness.

"I was very, very cold and it was black. I couldn't see anything," says Okene, staring into the middle distance.

"But I could perceive the dead bodies of my crew were nearby. I could smell them. The fish came in and began eating the bodies. I could hear the sound. It was horror."

After his rescue, Okene spent another 60 hours in a decompression chamber where his body pressure was returned to normal. Had he just been exposed immediately to the outside air he would have died.

The cook describes his extraordinary survival story as a "miracle" but the memories of his time in the watery darkness still haunt him and he is not sure he will return to the sea.

"When I am at home sometimes it feels like the bed I am sleeping in is sinking. I think I'm still in the sea again. I jump up and I scream," Okene said, shaking his head.

"I don't know what stopped the water from filling that room. I was calling on God. He did it. It was a miracle."