A New Zealand fishing boat, sailing in an area it would not normally be, has performed a miraculous rescue of three teenagers who had been lost at sea and had started drinking seawater.

They had eaten just one seagull in 50 days adrift.

The boys had disappeared from Atafu Atoll, north of Samoa and part of the New Zealand territory of Tokelau, on October 5.

An extensive RNZAF Orion search failed to find any trace of them.

On Atafu, 500 people had already held memorial services for Samuel Perez and Filo Filo, both 15 and Edward Nasau, 14.

"We got to them in a miracle," First Mate Tai Fredricsen of the Bay of Islands said this morning from the South Pacific.

The boys had drifted 1300 kilometres across empty and little travelled Pacific until they found themselves across the bow of San Nikunau, a Sanford tuna boat racing home for Auckland.

They were just west of Uvea in the French territory of Wallis and Futuna and north east of Fiji.

"Yesterday we saw a small vessel, a little speed boat on our bows, and we knew it was a little weird," Fredricsen told Stuff.

"We had enough smarts to know there were people in it and those people were not supposed to be there."

About a mile out the boys started waving to them.

"I pulled the vessel up as close as I could to them and asked them if they needed any help… they said ‘very much so’, they were ecstatic to see us….

"They were very skinny, but physically in good health, compared to what they have been through. "

Fredricsen, who is the medical officer on the ship, knew to be careful not to feed them or give them water quickly, and instead put them on an i/v drip.

But they were able to sip water and soon wanted real food.

"They are in incredibly good shape for the time they have been at sea."

The boys had a couple of coconuts on board but no water.

"Somehow they caught a bird, I don’t know how, but they caught it. They ate it, that is what is recommended."

But that was all they got.

Occasionally it rained, but in the days leading to yesterday’s miracle, there was no rain.

"They were having little sips of seawater, which wouldn’t have been a great idea, but they had only done it for the last couple of days."

He agreed that with drinking seawater the boys had only days to survive.

"It was a miracle we got to them."

After the boys had some food, they phoned home.

The other miracle was that San Nikunau was even there. The boat had been fishing in Kiribati waters and would normally off-load its catch in American Samoa. Instead they were coming home.

"We generally don’t take this route and we were following the fastest line to New Zealand."

As Fredricsen spoke, young Samuel walked onto the bridge with a big smile, but was too shy to talk to the media.

"They’ve just had a big kiwi breakfast and now they are ready for lunch. They are happy."

The boys are expected to be put ashore at Suva tomorrow.

To get to Atafu, though, they will have to fly to Samoa and then take a boat trip back home – Tokelau, New Zealand’s northern most point, has neither airport nor harbour.