(FORTUNE Small Business) – In a recent issue of Transworld Surf, a trade magazine, Randy French was listed as the third-most-powerful person in the $4.5 billion industry. But if there were a list of the most controversial players in the field, French would probably come in No. 1.

Through his Santa Cruz, Calif., company, Surftech, French is dragging surfboard manufacturing into the age of mass customization. For decades boards have been built by hand, shaped by craftsmen who cut and sanded blocks of polyurethane foam into the desired forms (longer for more stability, shorter for more maneuverability), then coated them with fiberglass and resin. Unfortunately, even the best shapers often couldn't predict how their boards would perform in the water. French, 53, who shaped boards in this way for nearly 35 years, had a rule: "I always got to ride the board first," he says. "One time I rode a board that I liked so much, I gave the friend who'd ordered it his money back. I think he's still mad at me."

French kept the board because he knew how hard it would be to replicate what he had done: create what surfers call a "magic" board. But in surfing, as in so much else, technology is changing everything. Last year French's company produced 50,000 "magic" boards. By using computer-aided-design programs, injection-molded technology, and a factory in Thailand, Surftech takes proven boards from the best shapers in the world and mass-produces them in a stronger, lighter material. Some 47 legendary shapers now sell their best designs through Surftech in exchange for licensing fees of about $35 to $50 for each board. With sales of more than $17 million in 2004, Surftech ranks as the largest manufacturer of surfboards in the world.

The company's modern approach has put it in the cross hairs of opponents. Critics say that by designing a board on a computer and producing it from plastic in an overseas factory, Surftech is destroying the soul of the sport. Purists also say that in the water, Surftech products lack the feel of traditional polyurethane boards; the new ones are stiffer and more buoyant (though they also don't break as often).

Two recent developments should help Surftech's image. Earlier this year six-time world champion Kelly Slater lent his name to a series of Surftech boards. Slater, one of the most famous surfers in the world, has publicly expressed frustration with the fragility of polyurethane boards (he once broke three in a session in Indonesia), though he still rides them in contests. Perhaps more important, a top professional surfer recently used a Surftech board in competition. At the 2004 Quiksilver Pro contest in Australia, former world champion Sunny Garcia became the first pro to win a heat on a Surftech. He didn't win the event, but the surf press and online chat groups took note of his equipment.

French got the idea of mass-producing surfboards in 1985, when he crafted a sailboard for a top-ranked windsurfer. Applying his knowledge of surfboard design, French built a smaller, lighter sailboard. The model performed well on the World Cup Tour and brought French an avalanche of orders. He knew he couldn't fulfill them if he had to produce the boards by hand. Another local business, Santa Cruz Yachts, was using composite plastics to mass-produce fast, ultralight boats (one of which set the speed record for sailing between Los Angeles and Honolulu). French realized he could employ a similar process for sailboards. Within a few years, he had two factories operating at full capacity to produce his sailboard designs. (Windsurfers, less tradition-bound than surfers, didn't gripe about mass-produced boards.)

Despite that success, French yearned to return to making surfboards. He also believed that the technology he had pioneered with sailboards could cross over to surfboard manufacturing. In 1989 he approached Cobra International, a manufacturer of plastic products in Thailand. In 1990, Surftech's first year in business, the company manufactured just 50 surfboards. For 2005 it is on track to make 75,000.

Surftech works with independent shapers, each of whom provides a master board--usually based on a popular existing model. (For more on how the manufacturing process works, see the box above.) The Surftech versions are called Tuflite--the brand name of the plastic from which they're made--but are sold under the name of the designer on whose model they are based. They cost substantially more--a six-foot Town & Country Tuflite model will cost about $600, compared with $500 for the foam version. But surfers are willing to pay a premium for what many consider a more consistent and durable product.

Not everyone agrees. "Board manufacturing has always been a hand-shaped industry," says Matt Biolas, head of surfboard manufacturer Lost and one of French's most vocal critics. "Surftech just softens the aura of what we have as a surfing culture, a sport based on individualism." Another critic is Gordon "Grubby" Clark, owner of Clark Foam, which makes the polyurethane blanks used by most U.S. surfboard shapers. Clark has written about the damage that mass-production can have on domestic surfboard sales, but he declined to comment for this article.

Criticism of Surftech's Thailand factory and allegations in the surfing community that the company was using sweatshop labor reached a peak in 2003. "The surfboard business is like junior high," says French in his Santa Cruz office, where an artist's model is posed behind his desk, making an "up yours" gesture familiar to Italians. "A lot of people don't function using sophisticated, refined business tactics. It's more like 'If you try to get in our business, we're going to kick your ass.'"

In response, French invited surf writers to visit the Cobra facility in Chonburi province, Thailand. A reporter from Surfing magazine wrote that he found a modern factory in an immaculate industrial complex located near companies such as Mitsubishi, Sony, and Toyota. In addition, French boasted that Cobra employees are unionized, earn above-average wages for the region, and receive health care, transportation, and subsidized meals.

At the outset, the shapers working with Surftech--almost all sole proprietors or small businesses--were concerned that their Tuflite models might cannibalize their higher-margin custom business. Their experience has been just the opposite, says Channel Islands Surfboards founder Al Merrick. "I think it has markedly helped sales in our core product," he says. "Tuflite is just 5% of sales, but it puts more product in the water, and more people see the logo. You get a customer that tries the Tuflite, and it's restricted in size by molds, so they may want to move to a custom board."

Another gripe is the difference in feel between the two types of boards. Yet, says French, "naysayers in the 1960s said the same thing when boards changed from balsa to foam." He points to sports such as auto racing and tennis, both of which saw enhanced performance after adopting composite materials.

At a recent trade show in San Diego, the Surftech booth was a hive of activity. The company introduced four new Kelly Slater signature models (different sizes for taller or shorter surfers, and for varying wave conditions) based on masters produced by Al Merrick, Surfing magazine's shaper of the year. There was also Robert August, star of the 1960s movie Endless Summer, who has models in the Surftech line. In the middle of it all, French moved easily among the celebrities of the surf world and the potential customers who asked him about the boards.

When asked what he's proudest of, French doesn't hesitate. "Last year we paid out a million dollars in royalties," he says. "Before Surftech, the pioneers of surfboard shaping had to be chained to their sheds to make any money. And shaping boards is hard work. Now these guys have something of a golden parachute, and surfers get to enjoy the legacy of their perfected shapes." If that makes French the most controversial person in the sport, he can deal with it.