Paul O’Leary said he usually swims a few times a week at Hawaii island’s Kehena Beach, but that routine was interrupted Tuesday morning when he felt something scrape his right foot.

O’Leary said he was about 150 yards offshore at about 10:30 a.m.

“I didn’t see anything but then my foot began acting weird,” he said. “I saw the flesh and skin kind of hanging there.”

O’Leary, 54, of Mountain View, became Hawaii’s eighth shark attack victim this year.

After the bite, he said he swam for more than 100 yards toward shore, yelled for help and several people assisted him the rest of the way.

He was taken by ambulance in serious condition to Hilo Medical Center, but it was unclear Tuesday whether it was a shark that O’Leary had encountered. Authorities took photos of his wound in order to help determine what caused it.

O’Leary said authorities returned Wednesday to tell him that he had definitely been bitten by a shark.

He was interviewed by officials from the Department of Land and Natural Resources, who said the wound was consistent with a shark bite.

He said the shark severed two tendons and a nerve in his right ankle area. He underwent surgery Tuesday night.

Kehena is a black sand beach popular among residents and visitors.

“There are a lot of people who swim there on a regular basis,” he said.

According to the state, O’Leary was using swim fins, and the splashing that is generated by fins has been known to attract sharks.

He said the water was murky when he was attacked.

“The visibility was not great, probably only 5 feet,” O’Leary said.

A medical laboratory scientist, O’Leary said he’s never heard of anyone being bitten by a shark off Kehena Beach, and he plans to continue swimming there — but won’t go as deep into the water.

“I used to go swimming alone,” he said. “I won’t be doing that either.”

The attack is the eighth confirmed in Hawaii in 2015, one of them fatal.

The number of shark bites has doubled in the past decade, the state said, averaging nine a year over the past five years.

Scientists say there are more people in the water, allowing more opportunities for shark encounters.