NEW ZEALAND: Lost Tourists Rescued From Bush

Two young Britons believe they're lucky to be alive after getting lost on a day walk in dense Marlborough bush and spending the night huddling next to a waterfall as temperatures dropped below zero.

Backpackers Stephanie Baker and Ryan Millward, both 23, say a wrong turn during an eight-hour hike through Mount Richmond Forest Park near Blenheim landed them in deep water, literally.

"I'm feeling like I'm lucky to be here right now," says Ms Baker, exhausted after finally getting out of the park at 5am today.

"We were wet, freezing, had no food and we were miles from anywhere. It was a nightmare. If it hadn't been for my phone and the people who came to get us ... they saved my life," she told NZ Newswire.

The pair, friends from Coventry, England, headed out early on Sunday to climb Mt Sunday and Mt Riley. They'd reached both summits without incident and were descending the last when they took a wrong turn.

Temperatures were as low as -6degC, and the pair found themselves in very steep and difficult terrain.

"We ended up clambering over rocks and down dangerously steep cliffs before we ended up by a waterfall in the middle of a valley, far from anywhere," said Ms Baker, who ended up having to swim through the falls to cross them.

"By then it was far too late in the day to go back up and try again. Calling the police was our only option."

Marlborough LandSAR volunteers walked for four hours in sub-zero temperatures, reaching the pair at midnight and then guiding them out of the park by 5am.

"I should be sleeping now but there's too much adrenaline. Thank God I'm alive," she said.