A spearfisherman has spoken of the heart-stopping moment he and a friend fought off a hammerhead shark as they tried to bring in a record-breaking yellowfin tuna.

Dom Simons and Craig Copik repeatedly poked and prodded the shark with their spears as it came towards them with its mouth open before Mr Simons landed the 270lb tuna.

The duo were part of a group of four spearfishing enthusiasts who travelled from Bermuda to Ascension Island in the middle of the Atlantic last month. The monster 270lb tuna landed by Mr Simons on the group’s last day on Ascension Island is believed to be the biggest fish ever speared by a Bermudian.

“It was just an incredible experience,” Mr Simons told The Royal Gazette.

“I don’t think I was ever scared for my life, I was more worried about Craig because he had recently become a father. It’s one of those once-in-a-lifetime experiences that I will probably never have again.

“To fight off a hammerhead and then bring in a tuna that big was simply unforgettable. I really only realised what had just happened once I got back on to the boat.”

The 28-year-old policeman and his friends hauled the yellowfin tuna on board their boat and brought it into land where it was weighted and then shared with the locals.

“We were surprised when a huge tuna turned up around 9.30am on the last day and even more so when a 10ft hammerhead made an appearance at the same time,” Mr Copik said.

“The shark was pretty determined to eat our chum bag, full of sardines, so we had to gently prod it away as it made repeated runs at us.

“Then we were lucky enough to experience something few people have ever seen with the tuna and hammerhead squaring off in a duel, battling for the chum that we had dropped to attract the tuna.”

He added: “During the whole encounter Dom, who was blue-water spearfishing for the first time in his life, kept his cool and lined up a shot on the bigger of the two tuna, stoning the 270lb fish with a head shot.

“Scotty Amos, who had spent the preceding days of the trip, teaching Dom various diving and fishing techniques, shot the second fish which was later weighed in at 238lbs.

“All the fish was shared among the local population of 800 people and nothing was wasted. It was a fantastic trip and one I hope to repeat next year with the same team.”