Right whales have every reason to distrust humans, since their sociable nature helped make them the "right" target for generations of harpoon-happy whaling captains. Nonetheless, an endangered North Atlantic right whale near Virginia Beach recently made the right call by giving a masked, knife-wielding human the benefit of the doubt.

The whale was tangled in fishing lines about 50 miles off the Virginia coast, where it was spotted by fishermen Pat Foster and Adrian Colaprete. They recognized it as a rare North Atlantic right whale, and moved their boat closer to see why it was swimming strangely. Realizing its predicament — loose fishing gear is the leading cause of death for large whales in the region — they eventually decided to try a rescue mission.

After studying the whale's movements, Colaprete got in the water with a knife and began approaching it. He also had the foresight to bring a waterproof camera, capturing the dramatic rescue of an endangered species that only has about 450 members.

"I started swimming toward it, and I couldn't see it because I was pretty far in front of it," Colaprete recounts in the video. "And all of a sudden, it kind of came out of the gloom, and it was almost like a submarine coming at me. It was kind of scary at first, but it was real trippy — as soon the whale passed me and I was parallel to its face and its eye, it kind of stopped … and gave me a little window to get down there."

Check out the amazing video below, which includes Colaprete's first-person footage of the rescue followed by interviews with both fishermen:

As Colaprete notes in the video, he only decided to help the whale because he's an experienced diver with a trusted colleague watching his back. North Atlantic right whales can grow to 50 feet long and weigh 70 tons, and one could easily kill a human without trying — especially if it's already thrashing around to escape entanglement. Getting close to a federally protected species is also a good way to get in legal trouble, even with good intentions. (Of course, it can be hard to resist a wild animal's apparent pleas for help.)

If you see an entangled whale, dolphin or other marine mammal in U.S. waters, the best way to help is usually to either contact onshore authorities or call the National Oceanic and Atmospheric Administration's Marine Animal Entanglement Hot Line at 1-866-755-NOAA (6622). See this NOAA page for more detailed regional and state contact information.

Related whale and dolphin stories on MNN:

Russell McLendon ( @russmclendon ) writes about humans and other wildlife.

Knife-wielding diver saves rare whale [Video]
After spotting a North Atlantic right whale tangled in fishing lines near Virginia Beach, an angler swims to the rescue with his knife — and his video camera.