THE SEARCH for missing Blathnaid Timothy has been extended along the east coast from Louth to Wicklow.
As the water search entered its third day today, gardai and the coast guard conducted helicopter sweeps of seawater along a lengthy stretch of Dublin Bay.
Gardai believe that the missing business consultant entered the water at Howth harbour after taking a taxi there from the city centre on December 14 last.
Hopes for the safe return of the 33-year-old have faded as the focus switched to the sea last Saturday, when the taxi driver who had picked up Blathnaid on December 14 came forward to tell gardai he had dropped her at Howth.
But searches there by the garda water unit and coast guard did not yield any clues into Blathnaid's disappearance, and now the coastline moving northward towards Co Louth and southward toward Co Wicklow is being scanned.
Gardai have also consulted local fishermen and marine records for information on tidal movements over the Christmas period.
Officers took possession of the woman's computer shortly after she was reported missing.
After examining the computer hard drive, and internet activity on the machine prior to her disappearance, they effectively dismissed a motive of foul play, the Herald understands.
Blathnaid's brother Ronan has said that his family is now seeking closure three weeks after she went missing.
"We are not very optimistic ... at this stage, the possibility is not good," he said.
"It's unfortunate but what we need now is closure. The focus is on the water, but we will have to wait and see."
Gardai are now satisfied that the last positive sighting of Blathnaid was on Harbour Road in Howth village at 8.30pm on Tuesday, December 14, after a large-scale media and garda campaign prompted the taxi driver who picked up Blathnaid to come forward.
Prior to this, the last sighting was at an ATM at Sir Rogerson's Quay at 8pm on December 14.
She was seen on CCTV taking €60 from the ATM before hailing down a black Mercedes taxi.
The missing person's team identified and interviewed the driver on Saturday.
Anyone with information can contact gardai on 01 666 9500 or the Garda Confidential Line on 1800 666 111.