Whistling strangers in the dark at 3am aren't everyone's cup of tea.
But they were everything to trampers Clive and Marie Cresswell in an early-Thursday rescue as they huddled in a makeshift bivouac in the bitterly cold 1500m altitude in the central Ruahine Ranges west of Waipawa.
In Hastings yesterday, recovered from the hypothermia which hit after a sudden deterioration of the weather towards the end of a four-day tramp, Mrs Cresswell, a 53-year-old nurse at Te Puia Springs Hospital, doubted she would have survived had it not been for the couple's $550 Personal Locator Beacon and the rescue party of four whistling and yelling strangers.
"I know it's a cliche, but it's the best money we've ever spent," said Mr Cresswell, 59.
Police Hawke's Bay search head Detective Senior Sergeant Martin James believes she wouldn't have survived if not for the PLB, and "some pretty ballsy stuff " from Hawke's Bay Land Search and Rescue chairman Michael Hawthorne, fellow LandSAR volunteers Michael Lydiard and Ben Watson, and Constable Jared Whitaker.
They trekked seven hours, including an hour in the chest-high Makaroro River, before clambering down 480m of rock, shingle, shale, tussock and leatherwood to reach the Tolaga Bay couple - in the dark, at 3am.
"They knew where they were," Mr James said. "It was just a matter of reaching them, and extracting them from the ranges."
The couple had entered the ranges from the Triplex Carpark on Sunday and were on their way back from a western crossing to Maropea Forks when the weather made its severe turn on Wednesday.
They were exposed coming over the tops (Te Atua Mahuru, at 1543m), to a very sudden change with a few hailstorms at right angles to the dumps with which Central Hawke's Bay had become familiar over the previous days.
"Up there, it's coming sideways at you," Mr Cresswell said.
As the weather closed in, Mr Cresswell realised he was also no longer able to "find" their route and they dropped down from the tops to shelter in a makeshift bivouac after activating the PLB.
It was picked-up at the national search and rescue co-ordination centre in Wellington, pinpointing their location down to mere metres, and the Lowe Corporation Rescue Helicopter Service was called in.
But the extreme conditions and the cloud t in the area prevented a rescue from the air.
With some contact with the couple via cellphone, and aware of a deteriorating situation it was decided to assemble a LandSAR team which entered the ranges about 8pm.
Mr Hawthorne went straight from his job as a carpenter, Mr Lydiard from his job as an orchardist and Mr Watson, an agricultural chemicals representative.
Mr Cresswell said he didn't expect to see anyone until the next day, and couldn't believe it when his wife woke about 3am and told him she could hear men whistling and calling out.
"Noooo!" Can't be," he said, thinking at best it was a bird in the wilderness.
"Then we heard shouting again," Mrs Cresswell said. "I've never seen him (her husband) move so fast, next minute he was up and shouting."
She said they were just as surprised to hear how the rescuers had reached them.
"The first thing I said was how did you get over the tops," she said. One replied: "Two steps, fall over, two steps, fall down . . . "
"It's a big climb up there," said Mr Cresswell, who with his wife has tramped the New Zealand countryside extensively over the last 30 years, including the Ruahine Ranges and sectors of the trip they undertook this week.
"I didn't expect anyone until the next day, I couldn't believe they had come all that way, in the dark. It was very heroic."
Mr Hawthorne, veteran of 35 years of searches, said the crew, packed with gear and supplies for themselves and the missing couple, chose to take the river route up to Colenso Spur rather than Sparrowhawk to avoid worse exposure to the weather, already severe with rain most of the way and 130km/h gusts when fronting the elements.
Mr James said Mrs Cresswell was exhausted when the rescuers arrived. "I am quite sure that had they not gone in that night it would have been a different ball game altogether."
The couple left Hawke's Bay yesterday for Rotorua to see one of their two daughters competing in a triathlon.