The three-man crew of Carl, Blake Sheridan (skipper) and Calum Mackay were fishing off Hicks Bay on the boat Doctors Orders.
They regularly fish together but this was the first time they had dropped their lines there.
Carl said they had been on the water for 90 minutes when his line started racing.
The moment it was hooked the fish ran out over 600 metres of line so they knew they had a big one on their hands.
The tuna took about an hour to reel in and it was not until they weighed it at Waihau Bay that they realised they had something special.
“We knew it was a big one, but not record size . . . she was a big night after,” Carl said.
The fish far surpassed anything Carl had caught in the past. He said his previous biggest effort was a short bill spearfish which weighed about 25kg.
Carl said the fish would be mounted and put on his wall as a trophy.
For the fish to be confirmed as a world record, a detailed application form must be filled out and a sample of the line used provided for confirmation by the IGFA,
The southern bluefin is the smallest sub-species of bluefin tuna in the world.
The all-tackle world record in this species is a 167.5kg fish caught at Tathra, Australia, in 2009.
The heaviest-ever tuna caught and recorded by the IGFA was a 1496-pound (678.6kg) bluefin in Nova Scotia in 1979.
