When Chelsea Crawford decided to go whale watching with a few friends in Mexico on Saturday she was hoping to spot a whale and maybe snap a photo.

The 19-year-old woman from Bridgewater, N.S., never expected to get slammed by the whale's tail. Or for the incident to go viral.

Crawford is in Mexico as part of a nine-month gap-year program with Live Different, a Hamilton-based charity that sends students on leadership excursions like the one in Baja.

"I just thought we would see whales. I just thought we would see whales in the distance and I was OK with that," she said.

But then eight or nine Grey whales surfaced, splashing around the boat. Crawford said the "friendly" whales were coming close to the boat and some people on the tour were patting them.

"I didn't get to pet one. I thought 'Aw, that's OK. Other people got to, that's fine'." 

She might have spoken too soon.

"We were just about to leave when this one decided to be very playful and decided to hit me," she said. "I saw it coming but I didn't know what was happening. All I remember is that I put up my hand towards my head at the end of it because the impact was crazy."

Crawford described the whale as "bony" and said she has a bruise on her shoulder.

"It's scary now thinking back at it," she said.

Her friend Taylor Roy caught it on video and uploaded it to YouTube on Sunday. As of Wednesday afternoon, it has about 897,000 views.

"We posted it because we wanted to share it with our friends and family in Canada...we thought we'd get 100 views," she said.

Crawford said she can't help but laugh at the situation now.

"My mom said, 'Oh Chelsea, only you could do this.'"

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