A rare, young white killer whale has been spotted and photographed in the waters off Nanaimo, B.C.

Researchers say it's been a decade since anyone's seen an orca like that in provincial waters.

"I had heard about them before, but I never thought in my life I would see one with my own eyes," said Val Watson, a naturalist with Vancouver Island Whale Watch. "I was just amazed."

Watson has spent hours on the water studying whales with the touring company. The pale orca caught her eye during a tour on Tuesday and sent everyone on board scrambling for a camera.

A rare, young white killer whale was spotted off the coast of Nanaimo, B.C., on May 28, 2019. 0:21

"We noticed that there was something a little weird about one of the whales: It was white," she said in a phone call Wednesday.

The juvenile whale looks like an average killer whale whose colour has been subdued by a grey-white film. Jared Towers with the Department of Fisheries and Oceans said that colouring means the orca likely isn't a full albino, which would probably be a good thing. Researchers say true albinos often die younger.

A white killer whale swims off the coast of Nanaimo, B.C., on May 28, 2019. (Vancouver Island Whale Watch)

Towers said the whale belongs to the Biggs killer whale family, which travels between southern California and Alaska.

Another white whale in the northern state sent researchers into a frenzy when it was seen near the Aleutian Islands in February 2008.

Biologists then had a similar reaction to the one Watson would have 11 years later.

"I had heard about this whale, but we had never been able to find it," Holly Fearnbach, a research biologist with the National Marine Mammal Laboratory in Seattle, told the Associated Press at the time. "It was quite neat to find it."

Another white orca was spotted once in the Aleutians years before that but has eluded researchers since.