humpback whale
Picture of a humpback whale taken off the coast of Puerto Lopez, Manabi, in Ecuador on October 21, 2015.RODRIGO BUENDIA/AFP/Getty Images

A video has captured an amazing moment of a giant whale pushing a snorkeller to rescue her from an attack by a large tiger shark near the Cook Islands in the South Pacific.

Biologist Nan Hauser was snorkelling off the coast of Rarotonga when a 15ft tiger shark tried to attack her. At that moment the 50,000-pound humpback whale swam in to protect the biologist from the "potentially deadly" attack.

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The incident happened in October 2017 but the video was released only on Monday on YouTube, and has since then gone viral. The video shows the whale pushing the biologist to safety.

Hauser, a 63-year-old Brunswick native, spoke to the Daily Mirror and shared her experience of the encounter. She said the encounter could provide proof of whales' nature to protect other species, including humans.

According to her, the whale pushed her with his head and mouth, tucked her under its giant pectoral fin for around 10 minutes and even lifted her out of the water on one occasion. She later realised that the tiger shark was close to her.

"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," Hauser was quoted by the Mirror as saying. "I never took my eyes off him which is why I didn't see the shark right away.

"[Humpback whales] truly display altruism — sometimes at the risk of losing their own lives," she continued. "Other fishermen and divers have seen this same shark nearby the reef and say that it is as big as a pickup truck. Some say that it is 20 feet long. It's funny how the tables are turned here: I've spent the past 28 years protecting whales, and in the moment, I didn't even realise that they were protecting me!"

"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," she said.

"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. 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."

Not just that, there was another whale that tried to keep the shark away from her.

"I never touch the whales that I study unless they are sick or stranded on the beach," she said. "In my head, I was a bit amused since I write Rules and Regulations about whale harassment - and here I was being harassed by a whale."

Hauser now plans to share the video with other scientists to expand research and awareness of such behaviour in whales.