A Navy boat is now on its way to the last known location of Kerry Blair's boat in attempt to find the Malborough man, now missing for more than a week.
The commercial fisherman is the brother of Tauranga man Peter Blair, who travelled to Picton and spent the week searching.
The Navy is expected to arrive late this afternoon, an update on the family's givealittle fundraising page said.
An Air Force Hercules aircraft would also assist the search, the update said.
The family thanked members of the public for their support, saying it was "hugely appreciated".
The page has raised more than $15,000 to help the search and rescue attempt.
An attempt to secure the vessel and bring it to shore had to be abandoned in heavy seas on Saturday.
Tasman police spokeswoman Barbara Dunn said Mr Blair's boat was spotted 200km off Taranaki by a Royal New Zealand Air Force orion.
A large oil industry ship equipped to operate in heavy seas was dispatched to try to reach the boat.
"The ship got to the boat but the seas out there were just atrocious and there was no way they could secure a line to it," she said.
They were not able to tell conclusively whether Mr Blair was still on board the boat. Another attempt would be made when the weather improved, she said.
They hoped a Navy vessel would be heading out to retrieve Mr Blair's boat but, if not, the family had a private vessel on standby.
Peter Blair said they had a 20m vessel and crew ready to go out once weather allowed, should the Navy decide not to make an attempt.
He said it had been incredibly frustrating for family, particularly Mr Blair's children, to get so close and have the rescue abandoned.
Mr Blair, 55, has been missing since Saturday last week when he launched his 9m aluminium boat, Erie, from the Marlborough Sounds.
The last sighting was about 5.30pm on Saturday near Cape Jackson.
Family had raised funds through givealittle.co.nz to put up a private plane to search for Mr Blair.
The Air Force orion joined the search on Friday and located the boat on Friday evening.
On the givealittle.co.nz page, family posted that they hoped a second rescue attempt would be made this morning.
"In the meantime, we have a private boat and team on standby if needed."
More than $15,000 has been donated to help with the search.