A once-in-a-lifetime encounter with a humpback whale in B.C.’s Haro Straight has sparked a stunning viral video – and a warning for boaters.

Jim Maya, owner of Maya’s Westside Whale Watch Charters on San Juan Island, Wash., took a group of whale watchers into Canadian waters earlier this month in hopes they’d catch a glimpse of one of the majestic creatures.

Despite it being a slow year for whale sightings, the group spotted the humpback in the distance, near D’Arcy Island just north of Victoria.

“We were just about ready to break away when it disappeared, so we went dead in the water,” Maya told CTV News. “Then all of a sudden it spyhops right next to the boat, maybe 10 feet off the boat.”

The delighted group of whale watchers could do nothing but watch for more than an hour while the curious creature swam underneath and around the boat while breaching and spyhopping – a whale behaviour similar to treading water.

“You take all those words that people use over and over again that have no meaning after a while like ‘awesome,’ ‘majestic, ‘gentle giant,’ and all of a sudden, they are so apt at that point,” Maya said.

One of the passengers, whale blogger Jeannie Hyde, shot a video of the breathtaking display that has since gone viral, going from thousands of views early Thursday to tens of thousands in a matter of hours.

“I’m taking no end of grief for calling it ‘honey’ and ‘sweetie,’” Maya said. “I’m a hard, bitten salty sea dog of a captain and here I’ve turned into this blubbering sentimentalist.”

Maya said he’s been traversing the waters of the Pacific Ocean since 1965, and has seen his fair share of whales, porpoises and dolphins – but nothing like this.

“I had my daughter call me from California to tell me she was in tears and how lucky we were to experience this,” he said. “It was a gift. It was something that transcends logic. I would love to see that whale again.”

The captain said he usually tries to keep clear of whales by 100 metres – the required distance set by the Department of Fisheries and Oceans in Canadian waters – but he didn’t want to take the chance of hurting the humpback by turning on his motor.

“As you can see in the video, this animal just wanted to be there for whatever reason,” he said.

A local whale expert called the boat’s whale encounter “an extraordinary circumstance,” but cautioned other boaters who may want a repeat performance.

“While this seems like a very neat situation for that vessel, it does raise flags in that we’re worried that other vessels may want similar experiences,” she said. “That can be very dangerous, both for the whales and for the people as well.”

A Campbell River man needed more than $10,000 worth of reconstructive surgery after a breaching whale collided with his boat in May – sending him flying and causing major damage to his vessel.

Birdsall said boats that get too close to whales can disturb their ability to rest and find food, and the ever-present threat of ship strikes can lead to injuries – or even death.

The good news is the population of the baleen whales is on the rise in B.C. and beyond.

“At the end of commercial whaling, there might have been as few as 1,800 in the north Pacific,” Birdsall said. “We now estimate there are well over 20,000.”

As for the incredible behavior displayed by the whale on Maya’s tour – Birdsall said it’s very likely the humpback was curious and wanted a better look at the boat full of humans.

It’s not something Captain Maya will soon forget.

“I was so in the moment and in such awe that I wasn’t frightened, and I don’t think my passengers were,” he said. “You are so impressed with the strength and the magnificence of that animal being so close to you, I just enjoyed it. There was nothing I could do, so I just enjoyed it.”

With a report from CTV British Columbia's Brent Gilbert