Passengers of a Vancouver tour boat were treated to an extremely rare sight when a pod of orca whales cruised into the waters underneath the Lions Gate Bridge Friday.

Those aboard the Harbour Cruises tour boat only coughed up about $30 for a one-hour sightseeing tour of the city, but they stretched their dollars considerably further when employees spotted two orcas – also referred to as killer whales – swimming east under the Lions Gate Bridge.

“We were jumping up and down. We were just like, ‘This is ridiculously rare, this never happens,’” said tour guide Nicholas Litt.

Passengers quickly crowded the rails of the boat to catch a glimpse of the graceful mammals.

Another guide suggested going to the back of the vessel to see if there were any more orcas in tow.

Sure enough, the group counted six whales in total taking a trip into the inlet.

“You could see that one of their dorsal fins was gigantic…maybe a metre-and-a-half,” he said. “We kind of scrapped the tour at that point.”

The boat followed the whales from a distance as they pushed on toward the Second Narrows Bridge, Litt said.

When that tour ended – and its satisfied customers disembarked – a new group boarded and the boat headed back toward the Lions Gate Bridge. So did a few of the whales, tour guide Kim Bartfai said.

“It looked like they were heading back in the opposite directions, under the bridge,” she said. “Sometimes you feel like there’s so much marine traffic going on…I have no idea if they just got off their mark.”

An animal encounter specialist for the Vancouver Aquarium said the pod – actually two families comprised of eight transient killer whales – was likely in search of food.

“It’s a couple of big males, some juveniles,” Jen Derwojed said. “We do have these whales go up through Howe Sound often enough, so maybe they were just trying to find some other good eats.”

Derwojed said the whales like to snack on harbour seals and porpoises.

With this year’s salmon run hitting its stride, an increase in seals may have drawn the animals to the inlet.

Sightings aren’t common for the location, she said. “The last time transient killer whales came through was in 2011 – when the Canucks were in the Stanley Cup Playoffs.”

For Bartfai, it was a once-in-a-lifetime experience.

“I’ve been a tour guide for years,” she said. “This would be the first time I’ve seen whales. I was just beyond excited that we actually could see them, that they were quite close.”

She said the inlet, which is about 500 metres wide in the area underneath the bridge, can become crowded with marine traffic at the drop of a hat – or the splash of a tail.

“Sometimes I feel like they may be a bit close, but I can understand why,” she said. “It’s hard to know what their communication is – did they know the whales were there? The inlet here is just so busy.”

She said one thing is certain – those who spotted the frolicking orcas can consider themselves fortunate.

“We are so lucky to even have the rare opportunity to see something like that, which is something that most people don’t even have the opportunity to see once.”