Conditions were calm as searchers hauled the fishing boat belonging to a missing couple in from the water.
The 5.2 metre pontoon was found capsized near Nugget Point.
But nearby there was no sign of 77-year-old Whetuki Kopua and 60-year-old Matekino Burling, known as Lou and Sam.
"While we've got a good day we're going to use every hour that we have on the water,” said South Otago senior police constable Murray Hewitson.
The missing couple left from Catlins Heads on a fishing trip yesterday morning.
"We knew his intentions were to head our past the bar at Owaka and head South to his two favourite fishing spots," said Mr Hewitson.
Sixty people have combed the coastline and up to 6 kilometres offshore since the pair failed to return before dark last evening.
Emergency beacons and flares were on board and untouched.
Searchers say it is unlikely they swam to shore because of the rugged coast line.
"Most likely they would have hung around the boat I'd imagine if it had capsized and hung on for as long as they could," said Search and Rescue member Carey Hancox.
The pair were experienced fishers and well-equipped for the conditions.
Mr Kopua has fished the area for almost 40 years.
"He knows his way around and knows what he's doing, but it's pretty unforgiving – the sea – you know, at times," said Mr Hancox.
With a cold snap forecast for tonight, hopes are fading the pair will be found alive.