Kayonne Hillmon of Macon, Ga., was enthralled with the massive waves that pounded the shoreline at Waimea Bay on Wednesday afternoon.

“It’s truly amazing,” said the 30-year-old Hillmon.

The waves don’t get this big in Georgia, said Hillmon, a traveling nurse.

Waves reached 20- to 30-foot faces on Oahu’s North Shore and 12- to 20-foot faces on the west shore Wednesday. Signs warning people of dangerous surf were posted at beaches. Yellow “caution” tape also stretched across hazardous areas.

After the worst of it subsided, a high surf warning was downgraded to an advisory that remains in effect until 6 p.m. today for Kauai, Oahu and Molokai.

Waves are expected to be 12 to 18 feet today on north shores and 8 to 14 feet on west shores.

Forecaster Ian Morrison of the National Weather Service said the swell is expected to continue to drop through the weekend. Tradewinds are expected to remain strong through Friday and decrease to light and variable conditions on Saturday and Sunday.

Lifeguards were busy Wednesday warning people to steer clear of the shoreline during dangerous surf conditions.

As of 4 p.m. Wednesday, four rescues and 1,100 preventive actions had taken place on the North Shore. Two of the rescues occurred at a surf spot called Himalayas. Another rescue involved an individual on a rental surfboard at the entrance of the Haleiwa Boat Harbor.

On the west shore, two rescues and just under 400 preventive actions occurred.

Lt. John Hoogsteden of city Ocean Safety and Lifeguard Services stood near the lifeguard tower at Waimea Bay, monitoring the surf and people.

“We’re doing our best to warn everybody,” he said.

Shayne Enright, spokeswoman of the city Emergency Services Department, said most of the crowds were at Waimea Bay, Haleiwa and Ehukai beach parks.

“We just continue to ask people to listen to the lifeguards, to stay back from the shorelines and off the rocks because that’s where we see people get hurt,” she said.

“It’s those people trying to take that perfect selfie and turning their back to the ocean. That’s when tragedy occurs, when they get knocked off their feet from the rocks and swept into the ocean,” Enright added.

The Billabong Pipeline Invitational surf contest at Ehukai Beach Park helped keep crowds contained there.

At Shark’s Cove, Steve Bradley and his wife, Christy, of Golden, Colo., who are on their honeymoon, stood along the grassy area watching large waves crash against the jagged rocks.

“We don’t get to see this every day,” said Steve Bradley, a first-time Oahu visitor.