"The first time I glimpsed the size of the fish was just seeing the head. It had been ripped off by teeth and all its guts was hanging out. I basically opened the giant jaws to retrieve my hook and it was weird, because I was looking down at daylight on the other side."
Moore said the line was "singing with the strain" of holding on to the catch, and he had bruises on his hand from where the rod had dug in.
"But I wasn't worried about being pulled in. It's actually a lot more stable pulling in a big fish on a kayak than you'd think, and because I was anchored, I wasn't being towed around."
The 53-year-old high school art teacher fishes from his 4m kayak most weekends. He said conditions on Sunday were slightly choppy and he never saw the shark that swiped his fish.
"My mind just sort of shut down. When you're in a kayak in the middle of the ocean you don't want to panic so i just got on with fishing. I just got this thing onboard and stowed it away and got my line back out there as quickly as I could and caught a big kahawai."
Kingfish can grow up to 2m in length. Moore, who only brought home 45-centimetres worth of his catch, says the head is destined for a soup pot.
"I went to bed thinking, you know, like in The Godfather, when there's a horse head? It was sort of like that. I went to bed thinking 'oh my God, I've got massive fish head in the fridge."
Moore says anyone who fishes is aware there are sharks in the harbour - he recently hooked one that swam under his kayak before snapping his line - but the experience has not put him off going back out.
"I'm not going to sell my kayak, but I am going to get a donger - something to hit a shark on the nose with if I have to."