Fisherman Terry Selwood was sitting on an esky in the middle of his small boat, enjoying the solitude of an afternoon's fishing off the NSW North Coast, when all hell broke loose in the middle of the ocean.

Out of the corner of his eye, the 73-year-old saw something launch itself over the side of his 5½-metre vessel, which was bobbing about two kilometres off the coast of Evans Head, on Saturday afternoon.

The next thing Mr Selwood knew, he had been knocked off his esky onto the deck, and was eye-to-eye with a large shark as it thrashed about next to him.

"There I was on all fours and he's looking at me and I'm looking at him, and then he started to do the dance around and shake, and I couldn't get out quick enough onto the gunnel [side of the boat]," Mr Selwood told the ABC.