A kayaker was rescued Friday afternoon after a passing paddleboarder happened to spot her curled up on a rock near the Huntington Lighthouse, where she swam after her kayak capsized, authorities said.

The unidentified woman, 54, of Huntington, had been kayaking in Huntington Bay when her vessel overturned, Huntington Harbormaster Ryan Sammis said.

The woman lost her cellphone and the kayak floated away, but she managed to swim to the rocks around the Huntington Lighthouse, Sammis said.

Despite the balmy weather, the water was 49 degrees — and clad only in a bikini top and shorts, the woman became hypothermic, he said.

Thepaddleboarder who happened to be passing by looked over at the lighthouse and spotted the woman, who by then was curled up into a ball and shivering.

The paddleboarder, who also was not identified, called his neighbor, Fred Uvena, a senior bay constable with the Town of Huntington, Sammis said. The paddleboarder, who had paddled over to the kayaker, gave the woman the top half of his wet suit in an effort to keep her warm.

Meanwhile, in addition to the harbormaster, the Halesite, Centerport, Northport and Huntington fire departments responded, as did the Huntington Bay police, said Dan McConnell, chief of department of the Halesite Fire Department.

The call came in about 12:43 p.m., McConnell said.

Uvena and Bay Constable Mike Callahan used a patrol vessel to retrieve the woman and wrapped her in a heavy coat for the ride back to shore, Sammis said.

There, she was evaluated, treated and released by Halesite EMTs, he said.

advertisement | advertise on newsday

“She had been stranded out there for a while,” McConnell said, but added it was unclear exactly how long she sat on the rock. It also was unclear why the kayak capsized.

Though the area is popular with boaters, paddleboarders and the like during the summer, it can be much less populated during winter, McConnell said.

“She got very lucky that that paddleboarder just happened to go by when he did,” he said.

Sammis said his crew later retrieved the woman’s kayak after the incident, which he called “unusual” for winter.

“A lot of it is the warm weather,” he said. “People think it’s a spring day. But the water is still 49 degrees. It’s cold.”