A Maine marine biologist says her life may have been saved by a humpback whale, who kept her away from a giant tiger shark.

Nan Hauser is the Executive Director of the Center for Cetacean Research and Conservation, and has often said she'll probably be killed by a whale someday. It's not a joke. She spends much of her time in the water, looking for and studying the giant mammals. So, when she saw a giant humpback whale in the water off the Cook Islands, she swam to it without hesitation.

But the Brunswick native told the Portland Press Herald, she started getting nervous when she got near the animal and it started pushing her around in the water. Hauser said the whale's eyes were huge, it was obviously trying to communicate something. The whale's movements were so aggressive, that the research group turned off a drone cam out of fear that they would record footage of her death.

Hauser says all she could do was stare at the whale and hope for the best. But she noticed that, despite the unusual way the animal was acting, it seemed to be protective, like it was trying to be gentle. When she got out of the water, she finally noticed a giant tiger shark swimming nearby and suspects that the whale was trying to protect her. Tiger sharks are known for attacks against humans. And whales often hide seals under their pectoral fins, just like this one did to Hauser, to protect them from predators.

The video of the encounter between Hauser and the humpback has gone viral. Hauser says, in all her years of studying whales, she's never heard of one protecting a human. Watch til the end to hear Hauser express her gratitude to the whale. It must have been an overwhelming moment.