Watch: Dramatic rescue of man clinging onto jetski for two hours near Whangārei

A couple who risked their lives to save a man smacked off his jetski in blustery conditions says they're "still kind of in shock".

Lewis and Alyssa Allen were sailing through Bream Bay near Whangārei on Saturday afternoon when they heard a mayday call over the radio.

The pair, who were only 5 kilometres away, called the coast guard, wrote down the coordinates, and steered towards the location.

"It was quite stormy and at one point we had a good 40 knot gust going into the wind," Alyssa told Newshub.

"I could see why someone would be in distress in this kind of situation."

 They spotted something that looked like a fishing net moving in the waves.
They spotted something that looked like a fishing net moving in the waves. Photo credit: Supplied

As they got closer, they spotted something that looked like a fishing net moving in the waves. The man, who had tied himself onto his jetski, had been clinging on for two hours.

"He was barely able to keep his head above water," Alyssa said.

"I yelled out, 'are you okay?' And he just kept laying there. He did not look good.

"At that point, I was like, 'Lewis, I'm going in'."

Without another doubt, Alyssa took off her layers, life jacket, and dived into the rough sea.

"He didn't really say much at that point. He was just so weak and his eyes were closed."

The man was in serious condition and had severe hyperthermia.
The man was in serious condition and had severe hyperthermia. Photo credit: Supplied

The pair managed to pull the man onto the boat and wrapped him in blankets before notifying the coastguard.

Northland Rescue Helicopter responded quickly and treated the man, who was in serious condition and suffering from hyperthermia.

The man, who had fallen off the jetski, said he couldn't get on as it kept capsizing. He eventually tied himself to the jetski and waited 

The couple, originally from San Francisco, have been living on their boat and spending the last four summers in New Zealand.

"I just can't believe it happened," Alyssa said.

She added, if he hadn't carried a personal locator beacon, he would have been dead.