SANTA CRUZ, Calif. — The screams filtered down as the Giant Dipper thundered above. Beneath the Santa Cruz Beach Boardwalk, the Dipper's 75-horsepower engine (the 1924 original) was pumping away.

SANTA CRUZ, Calif. — The screams filtered down as the Giant Dipper thundered above. Beneath the Santa Cruz Beach Boardwalk, the Dipper's 75-horsepower engine (the 1924 original) was pumping away.

The 83-year-old Dipper is the most popular of the boardwalk's 35 rides, but it's not the oldest. The carousel, with carved and painted horses, dates from 1911, four years after the birth of the "modern" boardwalk in 1907.

As California's oldest continuously operating seaside amusement park, Santa Cruz Beach Boardwalk is marking its centennial with a celebration of history and survival. Other seaside parks have given way to real-estate development, but Santa Cruz still attracts 3 million visitors annually with its tried-and-true formula of something for everyone.

"You have to reinvent yourself. It's a balancing act between introducing new activities and retaining your history," said Charles Canfield, who in 1984 succeeded his father, Laurence, as president of the privately owned Santa Cruz Seaside Co., which owns and operates the boardwalk.

As he spoke, an airborne pirate ship swished past his office windows. Farther down the boardwalk, riders of the Double Shot, the newest ride, were whisked 125 feet up, then down, to experience the weightlessness of negative G-forces.

That ride "gives you a thrill, but it doesn't scare you to death," said Canfield.

That's the boardwalk's comfort zone, even as other amusement parks push the envelope of what people can handle.

Even so, Canfield isn't likely to be aboard any rides.

"I don't like heights," he said.

He has taken each boardwalk ride once — and once only.

Santa Cruz Seaside Co. took over the boardwalk in 1915 from Santa Cruz Beach Co., which went bankrupt after setbacks — including a 1906 fire that consumed the original onion-domed casino. The casino-ballroom that opened in 1907 is now the Cocoanut Grove, a special-events venue.

Adjacent is Neptune's Kingdom, with a buccaneer-themed indoor mini golf course. Once, this was the natatorium, where water carnivals and shows featuring swim stars such as Duke Kahanamoku drew crowds to the saltwater plunge.

The boardwalk still provides old-fashioned fun along with corn dogs, cotton candy and deep-fried Twinkies. And promotion, as always, is part of the game. The Seaside Co.'s centennial book, "The Santa Cruz Beach Boardwalk: A Century by the Sea," recalls crawdad-crawl championships, bodybuilder and beauty contests and a Brussels Sprout Festival featuring deep-fried sprouts, sprout chip cookies and — for sprout haters — a sprout toss.

Maintenance is an ongoing challenge, said Canfield. Each winter, rides are X-rayed for cracks. Annual re-investment hovers around $3 million.

Canfield pointed out the Bulgy kiddie ride.

"This is one I ran when I was a kid," he said.

Not only has the boardwalk positioned itself as a family attraction — conceding the teen market to others — but there's also a boardwalk family of multigenerational concessionaires.

Marini's, which sells 19 flavors of saltwater taffy, caramel apples and homemade fudge, is run by Joseph Marini III, 34, whose great-grandfather, Victor, started out with a popcorn cart on the boardwalk in 1915. As a kid, Marini swept the floor of the candy store. Marini majored in biology in college but couldn't resist the allure of the family business and abandoned plans to be a dentist.

Ted Whiting III, the boardwalk's vice president of general services, belongs to a five-generation boardwalk family. In the 1950s, little Ted sat on the counter of the Bright Spot, ringing up sales. He was a teenager working the hamburger stand the day Walt Disney visited and asked for a burger, eschewing the fancy lunch boardwalk management had planned.

Whiting and his seven siblings grew up in the business, and four are still involved. The boardwalk, he said, is all about "current nostalgia."

"We don't want to divorce ourselves from the past," he said, "but we do want to stay current."

Great America, which opened in nearby Santa Clara in 1976, has a water ride, so the boardwalk introduced a water ride, Logger's Revenge.

Attractions perceived as tired or outdated (such as Autorama with its gas-engine cars) close; new ones open. On the drawing board is a multilevel haunted house. Canfield recently paid $250,000 for a rare Wurlitzer 165 band organ for the carousel building.

Located adjacent to a public beach, the boardwalk is not gated and admission is free. About 60 percent of visitors come for boardwalk attractions and 40 percent for the beach, though many hit the boardwalk for one of those corn dogs.

In the days when swimmers wore knee-length woolen suits, the arcade housed palmistry and astrology machines. Would a coin-fed psychic say the boardwalk will survive another 100 years?

"I think the psychic would say there's a good chance," Canfield said. "It's part of Americana that we really need to hang onto."