An Australian surfer has told how he managed to paddle back to shore and walk hundreds of metres to get help after being attacked by a great white shark.

The 29-year-old said he had been enjoying a "normal days surfing" yesterday on Kangaroo Island, off Australia's southern coast, when he had a sensation of "being hit by a truck" on his left side.

The surfer said in a statement: "It bit me around my back, buttock and elbow and took a chunk out of my board. 

"I got a glimpse of the shark as it let go and disappeared."

Police said a member of the public took the man from D'Estrees Bay and was met by paramedics while on route to the island's main city of Kingscote.

Ambulance leader Michael Rushby said he helped stabilise the man, who was suffering from "serious lacerations" before organising an emergency airlift to the mainland.

South Australia Police said the man's injuries are not believed to be life-threatening.

"I'm feeling incredibly lucky and grateful, and I'm optimistic I'll make a full recovery," the man said in his statement.

There have been eight fatal shark attacks in Australian waters so far this year, according to statistics maintained by the Taronga Conservation Society Australia.