But then the lights disappeared. Desperate, Okene swam through pitch-dark waters in the sunken boat to grab the diver. Okene couldn't find him and, with the air in his lungs giving out, he swam back to the cabin that held his precious, but dwindling, pocket of air.
In an exclusive interview with The Associated Press, Okene described the ordeal and his miraculous rescue that was videotaped and which went viral after it was put on the Internet this month.
The 29-year-old still has nightmares and vows to never return to the sea again. He has taken a new job as cook on firm ground instead.
Okene was the only survivor in a crew of 12 when the boat capsized in May. It still haunts him. In addition with being saddled with survivors' guilt, some Nigerians believe he saved himself through black magic.
The Jascon 4 was resting on the seabed upside down at a depth of about 100 feet (30 meters).
The chubby cook survived on only one bottle of Coke. Two flashlights that he had found gave up after less than one day. In the dark, he had almost given up hope after three days when he suddenly heard the sound of a boat, a hammering on the side of the vessel and then, after a while, saw lights and the rising waters around him bubbling.
He said he knew it had to be a diver, but he was on the wrong end of the cabin.
"He came in but he was too fast, so I saw the light but before I could get to him, he was already out. I tried to follow him in the pitch darkness but I couldn't trace him, so I went back."
His rescuers from the Dutch company DCN Diving were looking only for bodies and already had recovered four corpses when they came upon Okene.
When the diver returned, Okene had to swim again to reach him and still he did not see him. "So I tapped him at the back of his neck, so he was afraid." When the diver saw his hand he said "corpse, corpse, a corpse," into his microphone, reporting up to the rescue vessel.
"When he brought his hand close to me, I pulled on his hand," Okene said.
"He's alive! He's alive! He's alive!" Okene remembers hearing.
Okene described a surreal scene after the diver emerged into the air pocket.
"I knew when he gave me water he was observing me (to see) if I'm really human, because he was afraid," he told the AP last Thursday.
The diver first used hot water to warm him up, then attached him to an oxygen mask. Once saved from sunken boat, he was put into a decompression chamber for 60 hours before he could safely return to the surface.
Until his rescue, Okene believed his colleagues must have escaped. The tug was one of three towing a Chevron oil tanker in Nigeria's oil-rich Delta waters, but on May 26 there was a sudden lurch and it keeled over.
"I heard people shouting, I felt the vessel going down, going down, I heard a voice saying 'Is this vessel sinking or what?' ... I was in the WC (toilet) and the WC fell on my head, things started falling on my head ... My colleagues were shouting 'God help me, God help me, God help me.' Then after a while I never heard from them (again)."
When recounting the rescue at his local church, the pastor asked him if he had used black magic to survive.
"I was so surprised! How could a man of God be saying this?" Okene said, his voice rising in disbelief.
He didn't go to the funerals of his colleagues because he feared their families' reactions — Nigerians being generally very religious but also superstitious.
"I couldn't go because I didn't know what the family will say, thinking 'Why is he the only one to survive,'" said Okene.
It's a question that has shaken his steadfast faith. "Every week I ask (God) 'Why only me? Why did my colleagues have to die?'"
His wife Akpovona Okene, 27, said he still suffers nightmares. "When he is sleeping, he has that shock, he will just wake up in the night saying 'Honey see, the bed is sinking, we are in the sea."
Okene said he made a pact with God when he was at the bottom of the ocean: "When I was under the water I told God: If you rescue me, I will never go back to the sea again, never."
Alamba reported from Lagos
Video from the AP interview: http://www.youtube.com/watch?v=xrO2ENzr2cM
Video footage of Okene's rescue: http://www.youtube.com/watch?v=ArWGILmKCqE
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