Three helicopter crew miraculously survived after crashing into the freezing ocean near the remote Auckland Islands and swimming to shore injured in the dark of night.

Helicopter pilot Andrew Hefford, paramedic John Lambeth and winchman Lester Stevens were recovering in Southland Hospital last night after they were found yesterday on a beach on one of the subantarctic islands, 450km south of New Zealand.

Southern Lakes Helicopters CEO, Richard Hayes found the men and told Tim Dower it was the best and worst day of his life.

"It was worst night, the longest night and the whole trip to the Auckland Islands yesterday was virtually flown in silence because we were expecting the worst."

"It turned around 180 degrees...where we were absolutely elated to see three orange-clad figures standing on the beach."

He said the rescue mission was particularly hard because it was so close to home.

"We have done hundreds over the years [rescues] but when it comes close to home it really, really is hard and yesterday was the hardest. These were all key personnel, that have worked with us for years and the thought that we had lost them was a pretty hard pill to swallow, but it certainly was a great trip home."

He said all three men were wet and cold when they were found as well.

"They were wet and cold. Obviously in a night out camped in the bush, it's pretty cold down there...so they were pretty glad to have a cup of coffee and a bit to eat."

Winchman Lester Stevens was knocked unconscious when the aircraft hit the water, and has no idea how he extracted himself from the wreckage, Hayes said.

"He was knocked out on impact, has no idea how he extracted himself from the aircraft, maybe it goes back to the training that everyone is required to do for any oceanic flights, but he came to out in the water and everyone else was out in the water. The aircraft was still floating at that time I believe, so then they were left on their own for a 20-minute swim to shore."

He said the crews ingrained training was critical to their survival.

"The survival instinct kicks in and the training is ingrained and it most certainly helps."

The three men had flown to the area to evacuate a sick passenger on a vessel and had planned to stay the night at a Department of Conservation (DOC) base on Enderby Island before attempting the rescue the following morning.