She said the incident is proof of whales' nature to protect other species of animal - including humans - and believes an event like it has never been captured on film.
Anyway, and quite out of nowhere, the whale suddenly sort of pushes Hauser away with its giant fin, for reasons that Hauser says were not immediately clear to her.
Lurking near the mammal and Nan, 63, was a 15-foot tiger shark. It was only when she saw the animal moving its tail left to right, instead of up to down, that she realized it was not a whale but, rather, a potentially unsafe animal swimming towards her. Her conclusion - as well as the conclusion of anyone who believes in universal goodness and needs some positive to cling to this awful week, even if it comes from perceived marine altruism - was that the whale was trying to save her. The POV video shows her swimming with a 25-ton humpback whale, which is one of those things that isn't risky and will never be unsafe yet still strikes me as EXCEEDINGLY unsafe, because of the part where she was swimming with a 25-ton sea beast, jeez look at the size of this thing.
"I wasn't sure what the whale was up to when he approached me, and it didn't stop pushing me around for over 10 minutes". It seemed like hours. "I was a bit bruised up".
"I've spent 28 years underwater with whales, and have never had a whale so tactile and so insistent on putting me on his head, or belly, or back, or, most of all, trying to tuck me under his huge pectoral fin".
"I tried to get away from him for fear that if he rammed me too hard, or hit me with his flippers or tail, that would break my bones and rupture my organs", she told The Independent.
She added: "If he held me under his pectoral fin, I would have drowned".
She added: "I didn't want to panic, because I knew that he would pick up on my fear. I stayed calm to a point but was sure that it was most likely going to be a deadly encounter", she continues. Several times during the encounter, Hauser attempted to calmly swim away, but the whale persisted in following her.
Renowned marine biologist Nan Hauser had an incredible close encounter with a 25-ton humpback whale in October 2017.
The biologist now hopes to share the footage she and her team were able to capture, in order to expand research and awareness of such actions from whales.
Ms Hauser said: "There is a published scientific paper about humpbacks protecting other species of animals, by Robert Pitman".
The biologist said she does not encourage touching whales.