"It's pretty exhausting, to be honest. But I'm really pleased."
The haul came towards the end of a spear fishing trip last Monday.
The fish were hard to see because they were so deep, she said. "I was about 15m when I saw the fish.
"I went a little further to get in range and then I took my shot."
Her spear hit the fish mid-body and stuck, allowing her to swim back to the surface holding the line.
"The fish was 20m down and pulling with all its might. It's pulling me down and I'm pulling it up. Sometimes I won, sometimes it won.
"One minute you're on the surface the next you're a couple of metres down before you even know it."
At one stage the strong current sucked her into a narrow channel between an island and a rock while she desperately clung to the line.
But after a 12-minute tug-of-war, the fish came close enough for her to fire a fatal second shot.
"The problem with a powerful fish like that is if it's not pretty much dead when you grab hold of it, it can really beat you up," she said.
Potter described her hobby as relaxing and addictive.
"And it's beautiful: you get to hang out with the fish and the seaweed and see the underwater world in its natural state in silence.
"I also just really enjoy hunting and gathering."
The fish has been filleted and is being smoked.
