The hotshots competing in the U.S. Open of Surfing in Huntington Beach, Calif., probably aren't thinking about back-to-school shopping.

But 14-year-old Kevin Collier, on the pier with his skateboard this week, had it figured out. When teenagers see famous surfers in clothes made by Volcom or Quiksilver or Billabong, the high school student said, they know where to spend their allowances.

"They like to see their heroes' brands on them."

This is no secret in Southern California and Orange County in particular, home to the greatest concentration of surf and skate companies in the world.

Star athletes are key marketing tools for the nearly $7.5 billion surf and skate sector, and they seem to have been doing their jobs: Apparel sales were up 9.9 percent in 2006 compared with 2004, according to the Surf Industry Manufacturing Association in Aliso Viejo, which conducts surveys every other year. (Sales of surfboards and skateboards and other hardgoods, as they're called, did even better, up 24 percent.)

Now, with the first day of school closing in, there's the chance to keep that wave going. Racks up and down the coast are loaded with backpacks with MP3-player compartments, slim pants and striped hoodies.

"You should see our store — it crushes at this time of year," said Scott Toth, manager of Huntington Beach Surf & Sport, across the street from the pier.

Young consumers who roamed the aisles this week will be back with their wallets open when the store's back-to-school sale starts, he said. "It will be like, 'Ooohh, I was just in there, I saw the new plaid jacket in the store. Boom, I'm going down.' "

Surf shops have plenty of competition as retailers nationwide engage in the annual ritual of reeling in schoolkids and parents, who have started snapping up sundresses, old-fashioned bluejeans and — the latest trend — just about anything plaid.

Last week, Wal-Mart Stores Inc. took the cheeky step of cutting prices on more than 16,000 products in what the chain calls "Operation Unbeatable." Among the noted bargains: Shorts for $5 and shirts at two for $9.

Families with school-age children are expected to spend an average of $563.49 on back-to-school purchases this year, up 6.9 percent from 2006, according to the National Retail Federation, the industry's largest trade group.

What will they be buying? The group predicts that electronic devices — including computers, iPods and cell phones — will rack up the biggest increases, followed by footwear.

But shirts and pants should also do well. At Becker Surf & Sport stores, dresses are "huge," co-owner Dave Hollander said. Apart from that, though, the industry hasn't produced any "must have" items beyond those under the broad plaid umbrella. "I don't see anything I'm going to stock the stores with and stand back and smile," he said.

So, to keep sales humming, it's important for the brands to be well connected to the athletes, and to the surf shops where many of them bought their first boards.

Huntington Beach is helping to bridge the gap between surfers and the companies that sponsor them this week as it hosts the Honda U.S. Open of Surfing presented by O'Neill, one of the sport's premier events. The timing — the event coincides with the launch of back-to-school shopping — could hardly be better for surf shops.

Sales reps from Billabong, Vans and Quiksilver have been trolling Jack's Surfboards in Huntington Beach to make sure they have plenty of products in stock, co-owner Ron Abdel said. At Surfside Sports in Costa Mesa, sales of board shorts and bikinis are tapering off while shoppers are buying more backpacks and T-shirts, said co-owner Duke Edukas.

"Many people already are thinking, 'I've got to get Johnny or Sally their back-to-school stuff,' " Edukas said.

Even though males account for the larger share of the industry's apparel sales, females are important in boosting revenue.

Women's apparel sales rose 32 percent to $327 million last year from 2004, according to the surf industry report.

Kelly Ridgedale, a 10-year-old from Canada visiting Huntington Beach with her family, said she wouldn't be impressed by a brand just because it was favored by a famous athlete.

"I wouldn't care if it was on a surfer," she said, "or just someone normal."