The search for missing Dunedin tramper David Palmer has moved into a fourth day but both police and survival experts remain confident that Mr Palmer could still be found alive.
Exhausted Search and Rescue Teams (SAR) combing North Otago's rugged Ahuriri Valley have been rotated but six teams remain in the field.
Up to 60 personnel were now involved with the search after the arrival on Tuesday evening of a NZ Fire Service command truck, along with an Airforce Iroquois, and seven Army personnel, Snr Sgnt Tony Woodbridge said.
Police say the weather may be a limiting factor in the search today, with cloud coming down and steady rain in the area. However, the air temperature in the area was relatively warm overnight.
The 53-year-old experienced tramper went to the Ahuriri Valley area on Saturday for what is believed to be a three- to four-hour tramp.
Police were concerned Mr Palmer, a diabetic, might have become disoriented.
Mr Palmer had yesterday been missing for four nights, but New Zealand Mountain Safety Council bushcraft programme manager Chris Owens said, although he did not know how well provisioned Mr Palmer was, it would still be possible for the University of Otago librarian to survive for several nights, even if he was only lightly equipped.
"If anyone is compromised, we would suggest that they stay keep still rather than keeping on the move. It is much easier for search and rescue people to locate anyone that way.
"We advise that they get some sort of shelter either they find one like a little rock bivvy or create one with rocks around them and use, fern, punga, whatever they can."
Although night-time temperatures have, at times, been low in the Ahuriri Valley, and Mr Owens said building a fire and laying ferns on the ground to help retain body heat was important, staying out of the wind could also prove vital to survival chances.
"The chill factor, wind with a cold air temperature will lower the temperature quite quickly, which is not a good thing."
He also advised that trampers keep up to date with safety information and advise on the www.adventuresmart.org.nz website.
Although originally the search for Mr Palmer had focused on a 200 square km site of the vast Ahuriri Valley Conservation Park, searchers today refined that to a more specific area of the conservation park's Dingleburn Track, following a sighting of the missing 53 year-old on Saturday morning.
Oamaru senior sergeant Jason McCoy said that the SAR teams on the ground had been conducting a foot search, and had also been aided by Search and Rescue dogs.
"The teams will conduct a foot search, obviously they are all trained in relation to tracking."
Friends praying
Friends of the Dunedin tramper missing in the Ahuriri Valley area since Saturday are praying for his safe return.
Close friend Elisabeth Lukeman said Mr Parker "is a resilient, experienced tramper and mountain climber ... and tough.
"And one of the most decent and kind people you would ever be privileged to meet.
"Many, many people, many, many friends are praying for his safe return. There are so many people praying for him. He is loved by many friends."
Mr Palmer, who is unmarried, was described as being a "proud, loved uncle and godfather".
The missing man works as a librarian at the University of Otago Health Science library.
He was raised in Oamaru and educated at Waitaki Boys' High School.
Reports Mr Palmer was an experienced tramper had given searchers extra hope as they search in the Ahuriri Valley Conservation Park.
From the North Otago police forward operating base at Birchwood, Senior Sergeant Jason McCoy, of Oamaru, said searchers were focused on a corridor 10km wide and 20km long around the Dingle Burn Track.
Yesterday, a ground search of a 200sq km area failed to find Mr Palmer.
