Rathlin Island, off the coast of County Antrim is not where you would expect to find a 6ft x 8ft, 222 lbs (100kg) fish.
But that is exactly what fisherman, Andy Logan managed recently.
He said: "I've caught a couple of big sharks before and some big skates. But I've never hooked into anything like that before.
"I actually thought I'd hooked a submarine...that thing was going for Scotland."
The sheer size, power and weight of the fish caught Hamish Currie, an experienced skipper of 35 years, by complete surprise.
"I had to pull the anchor off the boat and go chasing the fish in open water," he added.
"We chased the big thing for two miles."
Hamish and Andy have been fishing together as part of the Carrickfergus Specimen Hunters Club for around five years.
They specialise in catching fish that are above average size and weight.
Andy said: "Most people don't realise these fish exist off our coastline. That fish would be between 55-65 years old."
The two men also play an important role in monitoring fish stock in the Irish Sea and throw most of the fish back.
"There are boys that would just go out there, catch them and kill them and not realise they're big breeding fish," Andy said.
"He's back in there anyway. The next time I catch him he'll be about 300 lbs."
The County Antrim fisherman could now be set to play an important role in monitoring the type of marine life that exists in the Irish Sea.
Scottish fish preservation bodies are to supply them with equipment and Hamish and Andy will provide them with data.
"What they're saying to us is that 'you seem to be catching more of those skate, and record breaking skate. If we provide you with the stuff, will you start taking data for us?' - so that's our next plan." Andy said.