Footage has emerged of the frightening moment a man kayaking in Albany's King George Sound was rammed and circled by a great white shark up to five metres.

Vision from a helmet camera worn by Ian Watkins displays the kayaker's understandable panic at his close encounter 200 metres off Possession Point on Thursday afternoon.

"Whale charter, whale charter, whale charter, do you copy? Emergency, emergency, emergency," Mr Watkins can be heard saying on a hand-held radio to a nearby whale spotting boat.

"I've got a white pointer attacking the kayak.