Video showed a humpback whale smashing into and capsizing a boat. Biologists say the whale was likely just feeding.

• A humpback whale capsized a fishing boat off New Hampshire's coast, video showed.
• Marine biologists said the whale was likely feeding, not attacking.

A fishing boat about a mile off the coast of New Hampshire capsized on Tuesday after a humpback whale came out of the water and smashed into it, according to video of the incident.

The two men who were aboard the boat told local outlet WCVB that they hadn't seen the whale for a couple minutes when it suddenly popped up and came down on the back of the boat.

The video, which was taken by a pair of teen brothers who were on another boat nearby, showed the front of the boat abruptly tilting upwards before coming down on its side and eventually capsizing after the whale disappeared beneath the surface.

One of the men dove sideways off the boat while the other was thrown overboard, according to WCVB. Neither of them were seriously injured in the incident, with one telling the outlet: "It's kind of a miracle that I'm alive."

While some people online described the encounter as an attack by an angry whale, marine biologists saw the video differently.

"What I see is a humpback whale feeding on bait fish," Andrew Trites, director of the Marine Mammal Research Unit at the University of British Columbia, told Business Insider in an email.

Trites noted the video showed that the whale came up with its mouth open — a sign of feeding — as well as some airborne fish that the humpback was likely targeting.

"So no attack by the humpback whale, just an unfortunate accident for both the whale and fisherman," he said, adding the whale may not have even realized the boat was there.

Melanie Smith, a marine biologist and master's candidate at the University of New Hampshire, agreed that the whale appeared to be feeding.

Smith, who studies humpback whale behavior, said lunging for fish is a very common behavior for the species. The humpback will typically swim straight through a school of fish or krill and open its mouth, which appeared to be what happened in the video.

"It seems like the whale was fishing, the people may have been fishing or were finishing up fishing, and it was kind of a bad place, wrong time," she said. "The whale may have just misjudged where the boat was and then hit the boat."

The lunging behavior is different than breaching, when a whale propels itself out of the water typically with its mouth closed and can get most of its body into the air. Unlike lunging, researchers are not confident why whales breach, though one possible explanation is that it's done to communicate with other whales.

As for the humpback in the video, the whale may have been injured when it crashed into the boat. Trites said it was likely injured but that it was not possible to know if it was cut, bruised, or even fractured its jaw. According to WCVB, there were pieces of whale skin and blubber on the boat's engine cover, which was cracked.

Vessel collisions remain a threat to humpback whales, though typically, strikes by larger ships pose the greatest risk.

The biologists said the incident showed why it's important for boaters to maintain distance from whales, which can do serious damage to boats, even unintentionally, due to their large size.

"Hopefully, this video helps make others realize that they need to give whales space to feed rather than run the risk of having a whale come down on top of them," Trites said.