British swimmer Adam Walker completed an eight-hour-and-36-minute swim in New Zealand on Tuesday - and safely finished the challenge with a little help from a friendly pod of dolphins.
He was braving the freezing waters of the Cook Strait when he noticed a two-metre shark swimming below him.
But a pod of dolphins immediately began swimming beside him, and stayed with him for an hour while he made his way across the strait.
Mr Walker, who made the swim while raising money for the Whale and Dolphin Conservation Society via Just Giving, said he wasn't sure if the dolphins were intentionally protecting him.
But he told the Daily Mail: "It would be a nice thought they were thinking, we will just help our pal get through."
It was Adam's sixth swim as part of the Ocean's Seven challenge in which participants swim the seven hardest long-oceans around the world.
He even took to Twitter to share his dolphin experience, writing: "Swimming with dolphins on my 6th of Oceans 7 swims 'Cook Strait' open water swimming doesn't get any better than this."
It's not the first time reports have emerged of dolphins protecting humans against sharks in New Zealand.
Back in 2004, four swimmers were saved from a great white shark in New Zealand's Whangerei on the North Island.
According to the Guardian, Rob Howes, a British-born lifeguard, had gone swimming with his daughter and two of her friends when a group of dolphins surrounded them.
He said: "They started to herd us up, they pushed all four of us together by doing tight circles around us.
Then he spotted a three-metre [10ft] great white shark heading towards him.
He added: "I just recoiled. It was only about two metres away from me, the water was crystal clear and it was as clear as the nose on my face. They had corralled us up to protect us."