Surfers in Honolulu Ocean Safety were rescued by 20 rescuers on the North Shore of Hawaii, and the weather service dismissed a high surf warning

Honolulu Ocean Safety lifeguards, posted on beaches across Oahu, rescued 20 people on the North Shore on Wednesday, said Shayne Enright. They were also busy with thousands of “preventative actions,” she said.

A high surf warning remains in effect until Friday morning, but Paishon is taking advantage of the waves by surfing at various spots on Oahu.

Similar waves washed over the California coast and caused flooding, as well as prompting warnings for low-lying areas.

Forecasters urged people to stay off rocks and jetties, and to not turn their backs to the ocean because of the danger of “sneaker waves” — occasional much bigger waves that can run far up the sand and wash someone off a beach.

In Hawaii, which also was slammed by the huge swells this week, the weather service downgraded a high surf warning to an advisory Friday. Large breaking waves of 18 to 22 feet (5.5 to 6.7 meters) along some north-facing shores and strong currents will make swimming dangerous, the weather service said.

In the area of the parking lot on the beach, there was a lot of debris after the surf overran it. People in several coastal areas were told to be ready to evacuate.

While not quite as huge, the waves along Southern California were also described as hazardous, with life-threatening rip currents. Nonetheless, surfers couldn’t resist.

“I was waiting for awhile because the waves were really sick, and they’re kinda hard to get into even though I have a really big board,” he said. “Just waited for a good one and I got it and it was a long one. It’s pretty big. It was not good.

Giant sand berms in the Pierpont area of Ventura, Calif., as Hurricanes rolled over over the weekend

The Los Angeles-area weather office wrote that powerful cyclones over northern Pacific waters were sending 12- to 17-foot (3.6- to 5-meter) swells, creating “tremendous wave energy across coastal waters.”

The ocean was less violent Friday but the National Weather Service warned that another round of extremely dangerous surf conditions would return Saturday.

Eight people were taken to hospitals for treatment of injuries after the Pierpont incident, according to Ventura County authorities, who closed beaches, piers and harbors through Dec. 31.

Karris Kutivan, a 9-year resident of the scenic shoreline city, said they have had water down the lane once before, but never like this.

Dozens of people watched the construction of emergency barriers in the Pierpont area of Ventura, where a rogue wave smashed spectators and cars as it overran the beach and moved into a neighborhood.

VENTURA, Calif. — Bulldozers built giant sand berms Friday to protect beachfront homes in one of California’s coastal cities hit hard this week by extraordinary waves generated by powerful swells from Pacific storms.