WAIMEA BAY — Thousands from around the island and the world converged on O'ahu's North Shore yesterday to see the giant rollers that made this shoreline famous — and the surfers who became famous by riding them.

"Right now, we're in the Roman Colosseum," said Waialua resident Carlo Prado, as he stood on the crowded shoulder of Kamehameha Highway, looking down on the surfers at Waimea. Pablo Grabiel, 61, of California, who was standing nearby added, "we all see the warriors devoured by the lion."

About 25,000 people — from longtime surf enthusiasts to residents and visitors who didn't want to miss the biggest swell of the year — came out for the Eddie Aikau surf meet at Waimea, organizers estimated, battling traffic and grappling with limited parking to marvel at the monster waves up close.

And they weren't disappointed by Mother Nature's display.

Waimea was pounded yesterday with 30- to 45-foot surf. On outer reefs elsewhere on the North Shore, rare sets had 50-foot faces. The big waves caused no major damage, but they did spur problems, from traffic backups to parking head-aches to near-misses as people walked along roads to get to the beach.

Lifeguards were also busy throughout the day on north- and west-facing shores.

In all, lifeguards conducted about 10,000 "preventive actions," several assists and four rescues. After one of the rescues, a man required hospitalization.

That rescue happened about 12:32 p.m. at Mäkaha Beach Park, when a canoe flipped over in large surf. The injured man, who appeared to be in his 30s, was taken to a hospital in serious condition, said city Emergency Services Department spokesman Bryan Cheplic.

The North Shore swell isn't expected to last much longer. The National Weather Service predicted wave heights will be 25 to 35 feet this morning.

By tonight, surf is expected to drop below warning levels.

'EDDIE IS A GO'

Though the swell, which came in Monday, wasn't a history-maker, NWS forecasters said it was significant and one of the largest of the year. "We don't get these kind of swells every year," said Tom Birchard, an NWS lead forecaster.

Yesterday started with some uncertainty over whether the Eddie Aikau competition — largely considered the most prestigious big-wave surfing event in the world — would be held. The contest requires ridable waves with 40-foot faces.

But at 7:30 a.m., the decision was made.

"Eddie is a go," contest director George Downing told the crowd.

And they went wild.

"It's just a buzz to be here," said Katie Speed of Lä'ie. "It's just so exciting."

Speed was rooting for surfer Kelly Slater.

For many, yesterday started well before daybreak as they worked their way through bumper-to-bumper traffic in hopes of grabbing a parking space as close to Waimea Bay as possible. By 7 a.m., people were parking two to three miles from the bay and walking, biking or catching the city bus in.

Others opted to illegally park, jamming up sidewalks or blocking driveways.

Police said they issued dozens of citations yesterday to drivers, many of whom blatantly ignored "no parking" signs. Meanwhile, other drivers beat the lines by snagging spots as early as 2 a.m. and sleeping in their cars or trucks.

Mike Tasaka, 54, of Hono-lulu got to Waimea before dawn to meet his son, who had scoped out a space on the sand about midnight. "I just wanted to be a part of something special," said Tasaka, who was backing surfer Keone Downing.

The waves had people skipping work or school, and bringing friends and family. "This is so cool," said University of Hawai'i student Cecilia Durocher, 18, who cut classes yesterday with a group of friends to go to Waimea Bay.

"I like being a part of it," she said.

This season is the 25th anniversary of the Eddie Aikau surf contest, held on just one day in the winter — and only if the waves are high enough. Because of its wave height requirements, the event has been held just seven times before.

It was last held in December 2004.

Organizers said the crowds this year could be bigger than ever.

"I've never seen so many people," said Downing, the contest director.

Many attendees, too, were surprised at how many came out on a weekday to see the surf. "I don't think there's anybody in Honolulu," joked Toto Cogorno, 53, of Kahu-ku, as he scanned the jammed highway shoulders that surround Waimea.

FEARS AND HOPES

Yesterday was the second day of the swell that brought big surf to O'ahu's North Shore. Forecasters had warned the swell had the potential to bring 50-foot waves to shorelines. Some feared it would match the might of a swell in 1969, which swept away homes and cars on the North Shore and killed several people.

At the same time, many also hoped that the surf would be large enough to hold the Eddie Aikau meet. Thousands gathered at Waimea on Monday, only to be met with lower-than-expected wave heights well through the afternoon.

Winds beat down wave heights and made conditions choppy. By mid-afternoon, though, the surf was picking up and the waves were cleaner.

On Monday night, Eddie Aikau organizers said the competition was almost certainly on. Yesterday, Eddie Aikau's sister, Myra, said it's heartwarming to see so many coming together to celebrate the memory of a legendary surfer in a way that he would have most certainly approved of. Aikau was lost at sea in 1978 while attempting a solo rescue for the capsized Hokule'a voyaging canoe.

"There's massive people out here," Aikau said. "It's just a beautiful day."