Search and rescue crews, two helicopters and other emergency services yesterday converged on Moeraki after a report a boat had capsized about 500m from shore.
However, nothing was found after a search lasting about 90 minutes.
Sergeant Tony Woodbridge, of Oamaru, said a phone call was received at 12.36pm from a Moeraki resident who thought they had spotted a boat with a white hull capsized off Moeraki.
Later, police were told it appeared the boat was in trouble.
Helicopters from Dunedin and Hampden with Dunedin water rescue squad members on board were called in to search for the boat.
An Oamaru ambulance, police and the Hampden Fire Brigade were also called out and the North Otago marine search and rescue notified.
The crews of three Moeraki boats went out to search the area.
Sgt Woodbridge said the sea was relatively calm, with visibility of between 5m and 10m down into the water.
After searchers found nothing, the search was called off about 2pm.
