A researcher's close encounter with a sperm whale near Alert Bay is believed to be the first confirmed sighting of the elusive animal in B.C. coastal waters.

Jared Towers, a cetologist with Fisheries and Oceans Canada, says the research station OrcaLab picked up acoustics of a sperm whale in the Johnstone Strait about a week ago.

They contacted Towers and he set out looking for the marine mammal, which is known to dive up to 2,000 metres and can stay submerged for up to 90 minutes.

"I've been looking at whales here on a regular basis since I was a kid, and I've not known of any reports of a sperm whale in this area, nor has anyone ever visually confirmed one here," Towers said.

The last time a sperm whale was even detected in the region was in 1984, when researchers picked up acoustic recordings.

But Towers and colleagues hit the jackpot in the west part of Johnstone Strait Tuesday.

They found the whale they had been tracking for nearly a week and discovered it was an adolescent male about 14 metres long.

"Seeing is believing," he said. "It was pretty radical…We got lucky and when that species comes up to the surface, they can't really move around a lot or dive again right away."

As a permitted research vessel, the boat got up close to the whale to get identification photos of its left and right dorsal fins.

Towers later posted pictures and a video of the encounter to Facebook, where they've been shared more than 800 times.

He said he's now fielding questions from people concerned that the whale was sick or lost, but he's not worried.

"Behaviourally and physically it seemed quite healthy. I think that if it found its way into the strait, it knows how to get out," he said. "That fact that it's here, it could be that sperm whales are finally starting to recover from whaling."

The species was decimated by whalers in the 19th and 20th centuries, leading to a significant population decline and their subsequent protection by the International Whaling Commission.

Towers said the whales may have been coming into the B.C. coast on occasion more than 100 years ago, and hopefully, the latest sighting is a sign they may be on the rebound.