A whale watching tour group in the Bay of Fundy got a rare treat during the last trip of the season Friday.

A male killer whale swam right up to the boat. Orcas are a rare sighting in Atlantic Canadian waters.

Durlan Ingersoll has spent the last 20 years working as a guide aboard Grand Manan’s Sea Watch Tours.

On Friday, Ingersoll was out on the boat with a group of naturalists from Nature Moncton.

He said they saw a research vessel from the New England Aquarium in the distance. Usually the vessel is on the look out for endangered northern right whales, so Ingersoll said they radioed the vessel to ask what the crew was looking at.

He was surprised to hear the crew had spotted, not one of the expected whale species, but a killer whale — a species associated with Canada’s west coast.

"I was very surprised to see the tall, tall dorsal fin at two miles away as it was swimming along," said Ingersoll.

He estimates the whale's dorsal fin was about 1.5 metres tall, a good indication this was a male.

Male orcas tend to have much larger, straight dorsal fins compared to females which have comparatively shorter, more curved dorsal fins.

"It was quite an incredible sight," said Ingersoll.

"It went down when we got there, and the first thing it did, it came up alongside the boat, like within 10 or 12, maybe 15 feet away. Just incredible. You could see it coming up underwater."

Ingersoll said it’s been 16 years since he last saw orcas in the Bay of Fundy. He said seeing this whale was one of the most incredible things he has seen in his 20 years as a whale watching guide.

Ingersoll said it’s been 16 years since he last saw orcas in the Bay of Fundy. He said seeing this whale was one of the most incredible things he has seen in his 20 years as a whale watching guide. (Courtesy Durlan Ingersoll)

"This is way up there. This is incredibly rare. I think a couple of years ago I had heard there was a lone killer whale off of Nova Scotia somewhere, whether it’s the same one or not I have no idea. This is really satisfying to see this animal, this close too," he said.

Killer whales are the largest member of the dolphin family and are easily recognized by their distinctive black and white markings and giant dorsal fin. Adult males may reach lengths of eight to nine metres and weigh up to five tonnes.

West coast populations are listed as threatened in Canada.

Ingersoll said the sighting was a treat for everyone aboard.

"They were as wound up as I was. I have a tendency to get wound up and these people out there — this was all a first for all of them, except for the captain, Peter Wilcox, and I because we had seen them 16 or 17 years ago, but to find this, to get to see this whale in the Bay of Fundy is pretty remarkable," said Ingersoll.