For the second day on Sunday, police, rescue crews and Flinders Island residents spent hours scouring the shoreline and ocean for traces of the man, who was fishing with a friend on rocks at the mouth of the North-East River when the incident unfolded.

Police, rescue crews and the community will search again for the third straight tomorrow.

Inspector Michael Johnston said police were desperate to give the family closure.

- By police reporter Chris Clarke

EARLIER Sunday 9am: Police say they hold little hope of finding a missing fisherman alive.

A search for the man was called off at nightfall on Saturday, but will start again at 7am on Sunday.

The Westpac Rescue helicopter, up to 10 boats, and 14 people on land will take part in the search.

EARLIER: POLICE are searching for a man who slipped and fell into the water while fishing from rocks on the north of Flinders Island on Saturday morning.

The man, aged 42, of Lady Barron, was shore fishing with a male friend when he slipped off the rocks as he tried to retrieve some tackle that had fallen into the water.

A nine-hour sea and air search failed to find the man. The search will resume at daybreak on Sunday.

Tasmania Police have described the man as a non-swimmer and are concerned for his safety.

Flinders Island Senior Sergeant Russell Judges said it was a grim situation.

He said water temperatures sat around 11 degrees and the risk of hypothermia was high.

"If he hasn't got himself to shore, drowning is a major issue. I'm very, very, very concerned," Senior Sergeant Judges said.

"Obviously search crews would have liked to have found him, but they will be back with enthusiasm."

Senior Sergeant Judges said the man fell into the water near the mouth of a river where there were strong tidal flows and some breakers.

He said up to 30 people were involved in the search, which included private vessels, police boats, the Westpac Rescue Helicopter and other aircraft.

The search conditions were favourable, with mild to light winds and minimal swell.