A group of tourists got the thrill of a lifetime this week — the rare chance to see a killer whale off the southwestern coast of Nova Scotia.

Shelley Lonergan, research coordinator and chief naturalist with Brier Island Whale and Seabird Cruises, said Wednesday afternoon's voyage started out as any other cruise.

"We got a call from another whale watch operator that he had a killer whale that was travelling with about 200 dolphins," she said.

Seeing a killer whale off Nova Scotia is a somewhat rare occurance, but even more rare is the fact that the whale seems to have befriended a school of dolphins. Killer whales, also known as orcas, have that name for a reason — they've been known to eat dolphins from time to time.

Lonergan said they had "35 excited people and four very excited crew," on the boat that day.

"I was just totally excited. I was jumping up and down I was so excited, it was great."

Ocean Explorations Zodiac Whale Cruises also saw the Ol' Tom Wednesday. They posted the video, below, on their Facebook page.

Some lucky tourists with Ocean Explorations Zodiac Whale Cruises got the thrill of a lifetime off southwestern Nova Scotia. 0:30

'Hard to put into words'

It was a treat, especially for tourists from all over the world, including Germany, Switzerland, the U.S. and Ontario.

"I was just so glad that people got to see him. It was such an experience. It was overwhelming. It's really hard to put into words."

Lonergan said the whale, about six to eight metres long, was very interested in the boat.

"He actually surfaced behind the boat and he stuck his head up … had a look at the people on the boat and then he swam the entire length of the boat on the right side," she said.

"He was rolled on his side so that he could look up at the boat. He was curious."

This isn't the first time the whale, dubbed Ol' Tom, has been spotted in the area.

"When we first saw him in 2006, he was a juvenile because he was smaller than he is now," said Lonergan.

"He's pretty easy to identify because he has a notch out of his dorsal fin. Also his saddle patch, [a white patch near the dorsal fin], which is unique to each individual as well. So we matched him to the whale that had been sighted in 2006. He's been sighted every two years since that initial sighting."

'Dolphins didn't seem to mind'

Seeing a killer whale off Nova Scotia is a somewhat rare occurance, but even more rare is the fact that the whale seems to have befriended a school of dolphins. Killer whales, also known as orcas, have that name for a reason — they've been known to eat dolphins from time to time. (Shelley Lonergan)

Ol' Tom has been sighted off Grand Manan, as well as Yarmouth and throughout the Bay of Fundy.

"He's travelling around southwestern Nova Scotia and he's been doing so for a number of years."

Lonergan said she's not sure what's bringing him here this time but he's likely following his gut, drawn here by the abundance of food of Nova Scotia's Coast.

"Usually it might be some type of fish that brings him in but I didn't see any indication of that on that day," she said.

The group stayed with the whale and his dolphin entourage for about an hour.

"He was swimming with them. The dolphins didn't seem to mind him being with them. So we had some really good looks at him," she said.