By Natalie Akoorie
Nat Davey doesn't remember stabbing two sharks in the head as he fended off their aggressive attack during a routine dive that within seconds had turned deadly.
But Davey, an experienced diver and retired commercial fisherman, said the reflex was instinctive and it was only when he watched footage of the terrifying incident that he realised how serious the situation was.
"It happened so quickly. I don't remember much of it. Not until we actually watched the footage back that night, it was like 'Wow, that actually happened'. Crazy stuff."
The 39-year-old from Mangonui in the Far North was on a diving trip last August with his partner Rochele Potter at remote Ascension Island, between Brazil and Africa in the South Atlantic Ocean, when the drama unfolded.
Davey speared a Yellowfin tuna for dinner and was pulling it in as two Galapagos sharks swarmed him.
"I didn't see the shark coming or anything like that. I shot the tuna and swam up and as you look back down, there's the shark following you back up.
"I thought 'Oh wow, ok'. That was at the stage when I realised this could go a bit pear-shaped because the shark didn't go straight on to the fish, it came in on me rather than the fish."
Davey, who has swum with Great White sharks and bull sharks before, was wearing a GoPro camera on his head which caught the entire episode.
He had to make a split-second decision whether to feed the sharks the tuna or try to get away.
"You generally find that if you feed them then they just expect it in the future. The sharks realise really quickly, if they hear the speargun go off or feel that vibration in the water, they think 'Oh free feed, let's go and eat it'."
To prevent the sharks following the divers Davey decided to keep his catch but the sharks weren't giving up without a fight.
"They were hitting me in the stomach, with their heads so I actually assumed I'd been bitten. That was when I screamed. I had let go of the tuna at that stage."
Davey reached down and grabbed his knife attached to a weight belt, jabbing it into each shark as it got close enough.
"I don't remember stabbing them in the head, bar watching the video. I definitely remember them pushing me around in the water."
He estimated they weighed between 150kg and 200kg each.
The skipper of the waiting dive boat saw the shark's tail come out of the water and Davey motioning for help.
In all there were three divers in the water and they each clambered on to the boat uninjured.
The next day Davey said the same two sharks came back but this time they were a bit more weary.
"You could tell it was the same two, they had the stab marks in the head."
In the past two months there have been two reportings of shark attacks at Ascension Island, which has a population of only 400, and can only be accessed by a British Military plane from England which takes civilians to the isolated island on two flights per week.
Davey said a woman swimmer and a male surfer had each been bitten by sharks in separate attacks but both survived.
Galapagos sharks are similar to New Zealand's bronze whalers, a species which sometimes attacks humans unprovoked.
Davey and Potter, 35, have only ever recorded one other frightening encounter with sharks, in Western Australia about three years ago.
"My partner was trying to shoot a sailfish in Exmouth and the [bull] sharks decided they wanted to eat her instead of the bait. That was the first real crazy experience we've had. She was alright. She just got a hell of a fright as they come in."
The couple set up The Adventure Club about 12 months ago but have been filming their diving and hunting trips for several years.
"We just want to show people what we do. We're just living life."
The couple went to Ascension Island so that Potter could shoot a world record, which she did, spearfishing a 97.1kg Giant Yellowfin tuna.
"We were there to chase the Giant Yellowfin tuna. We're not there to kill stuff for the sake of killing it. Everything that we do kill we utilise and eat."
Davey said since uploading the video on Thursday it had gone viral, with thousands of views and they had been inundated with requests for interviews from media around the world, speaking to the Herald first.