Officials are unsure how a woman ended up naked in the water three miles off the Newport Beach coast before being rescued Sunday.

A pair of kayakers found the 28-year-old around 10 a.m. She was calling for help about three miles out from the Newport Harbor jetty, said Sgt. D.J. Haldeman of the Orange County Sheriff’s Department Harbor Patrol.

According to Haldeman, the woman — whom authorities didn’t identify — was alone without a boat, a flotation device or even a bathing suit.

“She was completely naked,” he said.

The woman told Harbor Patrol deputies that she had been in the water since the night before.

She said she was swimming at around 5:30 p.m. Saturday near 19th Street when a rip current swept her out, Haldeman said.

At some point during the roughly 16 hours, the woman said, she took off her swimsuit “so it wouldn’t restrict her in her abilities to swim,” Haldeman said.

When Harbor Patrol deputies arrived in a boat to take the woman to shore, they were ready to treat her for hypothermia, but she seemed fine, according to Haldeman.

Jennifer Manzella, spokeswoman for the Newport Beach police and fire departments, said officials checked the woman’s story to make sure they hadn’t accidentally overlooked her on Saturday night.

A lifeguard would have been stationed near 19th Street at 5:30 p.m. Saturday, but officials haven’t found anyone who saw the woman go in the water, Manzella said.

The Fire Department couldn’t find belongings that the woman said she left on the beach, Manzella said. If a lifeguard had found the items unattended on the beach at the end of the day, he or she would have investigated, Manzella said.

Newport Beach lifeguard David Pratt said it would be impossible for a rip current to pull the woman three miles into the ocean. Usually, such currents dissipate 50 to 200 feet out. Even in the most extreme surf, they pull for only 500 or 600 feet, Pratt said.

The woman also was about three miles down the coast from where she said she had started swimming.

“She was really far out,” Manzella said.