More than 30 searchers combed an area around the Bull Creek district towards the coastline for a third consecutive day yesterday but found no sign of Dianne Lane-Wright (45).
A helicopter was used late yesterday afternoon and the search of the area east of Milton is expected to resume early today.
Sergeant Martin Bull, of Balclutha, said searchers had covered a lot of ground but had found no trace of Mrs Lane-Wright.
Today's search is expected to venture further inland and further north along the coast, towards Brighton.
When asked if police were still hoping to find Mrs Lane-Wright safe and well, Sgt Bull said there was still "every chance" she was alive.
He cited the example of Milton woman Maree Gorton, who went missing at Tautuku in early January and was found more than 24 hours later, in remote bush.
But Sgt Bull said the longer Mrs Lane-Wright was missing, the "more at risk she is".
Police are appealing for any sightings of Mrs Lane-Wright.
She is 1.5m tall, medium build with long, straight black hair.
She was last seen wearing a green jacket, blue nylon trousers and gumboots.
