They were weighed down with wetsuits and diving tanks and held back by their flippers, but Paul and Dillon Cane reckon divers have never scrambled from the water so fast.
The father and son were diving for crayfish off Great Barrier Island when they resurfaced to see several fins sticking out of the water, about 100m away.
Dillon, 18, said they thought they were watching dolphins or porpoises, but they soon realised they were orcas.
So they decided to swim towards their boat at Cape Barrier, off the southern end of the island.
"We started to swim around and this huge fin came around the corner and there was another pod of them.
"We jumped out on the rocks as fast as we could, which was quite difficult with tanks on and flippers and stuff, but we couldn't really get any further back because there were rocks behind us and we had all our gear on," Dillon said.
"So we stood about a metre away from it and Dad just said, 'It could get us if it wanted to, mate,' and I went, 'Yup.'
"It was a little bit too close for comfort. It came up and kind of turned on its side and grazed against the rocks and just looked at us for half a minute. It was cool. It turned on its side and just sat there looking at us just under the water.
"It was amazing. It just sat there really still and then just a flick of a tail and it pushed off and it was gone."
Paul Cane described the experience as life-changing.
"The dorsal fin's as tall as we are - 1.8 metres - and it would have been at least two metres through his girth and as big as a small truck. He was huge. We could have touched him. He was massive.
"We both know - and we've read, of course - that orcas don't harm you ... but when you're sitting in the water, you're not that confident of things that you've heard.
"I was thinking, 'I wonder if he's eaten my other son', who I couldn't see. He was under water."
The close encounter on January 7 was caught on camera by Blake Powell, who was fishing from a 5.5-metre inflatable boat.