Bishan Rajapakse may have gotten more than he bargained for when he was surfing off the coast of Australia Sunday morning.

The 38-year-old doctor was catching some waves at Sydney's Bondi Beach when a he got a bit too close for one whale's liking. In a slightly fuzzy video, a whale knocks the surfer unconscious with the flick of its tail.

According to Ninemsn, Rajapakse was surfing with a group when the whale swam up. The surfers paddled near the humpback whale -- estimated to be at least 40 feet long -- to get a better look when the large creature struck Rajapakse with its tail.

"We were watching it peacefully and then it looked like it was going away," Rajapakse told The Sydney Morning Herald. "It came back as if it were curious and suddenly I [realized] I was on the inside of a circle of surfers and it was just to the right of me."

After being slapped by the whale's tail, Rajapakse fell unconscious for at least 10 seconds as others in the group dragged him back to shore. He was taken to a local hospital and treated for potential back and neck injuries, as well as a concussion.

One onlooker described the moment of impact, recalling that the whole beach just gasped.

'[Y]ou just saw basically surfers, surf boards, swimmers thrown into the air like skittles," witness Lachlan Harris told the BBC. "I've never seen anything like it."

Australia's ABC News reports that more than 1,900 whales have been spotted near Sydney this year -- up from last year's count of 1,300.

Though humpback whales do not pose a great threat to surfers, they have the potential to cause injury based on their size alone. (Humpbacks range between 48 feet and 62.5 feet, according to National Geographic.)

In 2011, two humpback whales surprised a surfer and several kayakers near Santa Cruz, Calif., when they got a bit too close for comfort, and the whale lunged out of the water. At the time, scientists believed weather patterns were responsible for driving the whales' prey -- and whales -- closer to shore.

Update, July 9: There appears to be some confusion about the type of whale. The marine mammal in question may actually have been a southern right whale, which looks similar to a humpback is also commonly seen off the coast of Australia.

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