Police search teams are dusting off a 25-year-old missing person case in a bid to test their new gear.
Joe Freiman, a 64-year-old farmer, went missing during a hunting trip on Stewart Island in 1991 and was never found.
Search and Rescue will on Friday return to the area to resume the hunt for Mr Freiman in order to test a new radio transmitting tool they've been trialling.
About 70 police and volunteers from the Southern District will make use of the SARTrack system as they search the area on foot for two days with no air support.
"The search area is probably one of the most remote parts of New Zealand so it will be difficult for Police to provide good communications," Community Constable Dale Jenkins said.
"In any areas where cellular coverage is difficult, this radio tool can be particularly helpful."
He said the system allowed a controller to see where all members were and what areas had been covered in real time, along with allowing notes to be made.
Mr Freiman vanished after leaving his party at the Mid Big Glory Hunter Camp to go hunting along for a few hours on May 30, 1991 and failed to return in the evening.
Senior Sergeant Brian Benn said the situation was an ideal way to test the new gear, which would allow 11 different groups to use one system .
"This means we could potentially find people quicker, which means saving more lives and putting less demands on searchers in the future."
The teams will be rowed to shore from a ferry on Friday night before returning to Bluff on Sunday evening.
The equipment so far has only been trialled in small-scale scenarios.