The skipper of the crayfishing vessel K-Cee, Bruce Gordon, 42, and crew member Darren Allen, 37, have not been heard from since Monday.
It was initially hoped they had managed to get into two small dinghies they had on board, but wreckage from both of these was found late yesterday.
Inspector Lane Todd said police searchers and local volunteers would today focus their attention on Secretary Island, near where the K-Cee's semi-submerged hull was found.
"That's just basically where that initial wreckage was located and since yesterday we haven't found any other wreckage or anything else so we just really want to concentrate there.''
A helicopter would be used to conduct a shoreline search.
Two police staff had been assigned to assist the men's families full-time during the operation.
"It's obviously very emotional for them so as time goes on... obviously it's very hard for them.''
Hope was fading of finding the men alive.
"With the time that's gone on, with the amount of information and evidence that we've located, the outcome's not looking very positive,'' Mr Todd said.
