It's a horse - off course and at sea

Harbour Patrol and the Santa Barbara Coast Guard located the horse in the Santa Barbara Channel. Photo / Thinkstock

A horse was rescued 3.2km out to sea after it was spooked during a photo shoot on a Santa Barbara beach.

The 7-year-old white Arabian named William - and also Air of Temptation - bolted from the beach in Summerland.

"The initial call came in as a missing horse," CNN quoted Santa Barbara Harbour Patrol Officer Ryan Kelly as saying.

Harbour Patrol and the Santa Barbara Coast Guard located the horse in the Santa Barbara Channel, swimming towards oil rigs, an incident report noted. It had been swimming for about an hour.

Some men on a rig had spotted William and alerted authorities, the Huffington Post website said.

"It was a real needle-in-a-haystack kind of find," officer Kelly told msnbc.com.

"He looked like every other bird that was just sitting on the water," a reference to the white horse's nose and face above the water.

Rescuers made a makeshift harness, tying William to the side of the rescue boat to keep him buoyant.

The return took two hours, with the boat moving at about 1.6km/h.

"Some of the grunts and noises he was making along the way - we weren't sure how he was doing," Kelly said. "He was thrashing around."

William's owner Mindy Peters said the horse had never been swimming before.

- AAP