WAIMEA — Although wave faces reached as high as 40 feet yesterday, very little trouble was reported on the North Shore and west-facing beaches of O'ahu.

Officials said a low tide and preventive action by lifeguards made the difference.

The National Weather Service issued a high-surf warning yesterday afternoon and it will be in effect until at least noon today. The warning is for the north- and west-facing shores of Kaua'i and O'ahu and also for north-facing shores of Ni'ihau, Maui and Moloka'i.

There was also a high-surf advisory for north-facing shores of the Big Island until noon today.

Waves were expected to peak last night at 20 to 30 feet along north shores and 15 to 20 feet along west shores, before diminishing today.

The weather service also issued a high-wind watch, beginning this afternoon and through tomorrow. Winds from the southwest will be 30 mph, with gusts of up to 50 mph.

"The release said O'ahu could expect gusts in the 50-mph range, which normally isn't too bad, but right now everybody on O'ahu has those beautiful inflatable Santa Claus snow globes up," said John Cummings, county emergency management spokesman.

Yesterday, yellow tape was stretched across several North Shore beaches, telling people to keep out. Lifeguards were on the public address system warning swimmers about approaching big waves and telling them to move onto the shore.

At Waimea Beach Park, the yellow tape barred people from the left side of the beach, and no one was allowed to body-surf or bodyboard, said Kerry Atwood, an ocean safety officer at Waimea for 18 years.

"It's very dangerous when the big sets come in — the whole area goes underwater," Atwood said. "It looks like a sandy beach, but when the larger sets come, it surges and you're under six feet of water."

Waimea reported the only rescue, which was more of an assist, he said. A surfer was swept from his board and taken by the current toward the rocks on the left. The lifeguards guided the surfer over the PA system and two lifeguards helped him out, Atwood said.

Atwood said the surf conditions were very good yesterday at Waimea, adding that he'd heard that Waimea was the only good place to surf yesterday on the North Shore. Some 60 people were in the water, he said.

"We got probably the biggest crowd of the year surfing," Atwood said.

Clark Abbey, a longtime surfer, said the good conditions lasted longer than expected and he spent more than seven hours surfing waves from 10 to 20 feet (local measurements, which translates to 20- to 40-foot faces).

"There was a lot of sharing going on, good camaraderie," said Abbey, who was enjoying his regular day off from work. "You could say the waves tamed us."

The conditions were good enough to run the O'Neill World Cup of Surfing for half a day, but not good enough for the Eddie Aikau Big Wave Invitational held at Waimea Bay, said surf meet promoter Jodi Wilmott.

The morning conditions were good but challenging, and by noon waves two miles offshore foretold changing conditions, Wilmott said. They were breaking all the way across at once, which is not good for competition, she said.

"It would have been a life-threatening washing machine to keep people out there any longer than we did," Wilmott said.

Earlier in the day, police called the city Department of Emergency Management to help control traffic at Kea'au Beach in Makaha.

Waves were washing across Farrington Highway yesterday morning, Cummings said. Three volunteers were sent and they found five inches of sand and debris on the highway, he said.

"They provided traffic control in the area while state highway crews cleaned the debris," he said.

By 4 p.m. the lifeguards at Waimea called on the emergency management department to help close the park, Cummings said. People were asked to leave at about 5 p.m. when waves were at 20 feet, he said.

Reach Eloise Aguiar at eaguiar@honoluluadvertiser.com.