Whale watching can be hit or miss. This trip was definitely "hit."

A whale-watching tour boat and a humpback whale collided off the coast of Nova Scotia last week. Neither the whale nor any of the passengers were injured.

Video of the encounter was posted on social media by David Mulder, one of the passengers.

It shows a whale approach the boat underwater, then begin to dive. Its tail lifts high out of the water, then flips backward onto the bow of the Zodiac inflatable boat.

"It was more of a tap than a hit," said Guy Melville, the Zodiac's captain and employee of Brier Island Whale and Seabird Cruises.

He said the whale ran into the boat while the motor was off.

"We were shut down and all of a sudden a whale shows up at our front door," Melville said. "The boat was stationary and the whale was in motion. Then it did its handstand and was vertical."

100-metre buffer in effect

The federal government enacted new regulations this year prohibiting tour boats from coming closer than 100 metres to whales to protect the marine mammals from harm or harassment.

The buffer was aimed at protecting the critically endangered North Atlantic right whale, along with other species like the humpback.

Tour guide operators have welcomed the regulations and said they can still get close to the animals if the whales choose to approach the boat.

After reviewing the video, Fisheries and Oceans Canada officials told CBC News in an email it was "difficult to determine the specific sequence and context of what happened in this short video, other than the obvious contact of the whale's fluke with the vessel."

The department said marine animals inadvertently come into close proximity with people or vessels, but added the new regulations requires "even accidental contact" between a vessel or fishing gear and a marine mammal to be reported to DFO.

Taylor Hersh, a PhD candidate at Dalhousie University who studies sperm whales, said it's hard to say how frequently collisions between whales and boats occur.

Taylor Hersh said whales are curious and social, which might explain why the whale approached the boat. (CBC)

"It's a pretty difficult thing to quantify, likely because it's often underreported, so when they are happening, unless somebody gets a video or someone reports it or the whale watch operator reports it, we won't really know about it," she said.

Near the end of the video, chunks of the whale's skin can be seen flying through the air. Hersh said that's probably sloughed skin, which is skin that would normally come of the whale. She said the fact the boat was an inflatable one would have also minimized the chance of injury to the whale.

As to why the whale approached the boat, Hersh said that can likely be explained by the fact that whales are curious and social.

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