Swimmer heading to Somes Island rescued by boatie

A man attempting to swim from Petone to Somes Island was rescued by a boatie after suffering hypothermia.

The Lower Hutt man aged in his early 20s was one of a group of three swimmers and a kayaker who set off from Petone about 11.15am.

The swimmer became separated from the others but the kayaker stayed with him, said Life Flight rescue helicopter crewman Dave Greenberg.

"The swimmer got into a bit of trouble but the kayaker was able to get him aboard the kayak and did manage to wave down a passing boat who picked up the swimmer and brought him to the wharf at Somes Island."

He was helped by Department of Conservation staff and visitors to the island, who included an off-duty ambulance officer.

The Life Flight crew responded in the Westpac Rescue Helicopter with a Wellington Free Ambulance paramedic on board.

On arrival, the man, who had spent about two hours in the water, was conscious but quite hypothermic, Mr Greenberg said.

"He had been stripped out of his wetsuit and given dry clothes and wrapped in blankets."

The man was taken to Wellington Hospital in serious but not life-threatening condition.

Mr Greenberg said harbour conditions were quite choppy, but the other swimmers made it to Somes Island - a distance of about 3km.