Sprouting almost overnight, a maze of yellow tents and shiny aluminum bleachers covers a swath of Coney Island beachfront typically inhabited by sunbathers and sand castle builders.

The Association of Volleyball Professionals Crocs Tour is in town, and the sand will not be the same until the athletes pack up and move on to the next city.

Last weekend in Long Beach, N.Y., the Beach Tennis USA tour held a regional tournament, and it will return there for the national championships Sept. 2-3.

Touring sporting events are nothing new, but the sports event travel industry involving amateur participatory sports is growing. Recent studies suggest the events generate as much as $4 billion each year.

The industry includes events like soccer and softball tournaments, surfing contests and the N.C.A.A. Final Four. The tournaments attract young and old, male and female, weekend warriors and seasoned professionals. They may be traditional youth baseball tournaments that are held in the same stadium with new players and new crowds every year, but more often they are itinerant events, parachuting into communities and transforming beachfronts, parking lots and vacant fields for a few days each summer.

The events can attract a few dozen to a few thousand people, who spend money in local hotels, restaurants and shops. The trend is a contrast to high-profile professional franchises pursuing multiyear television deals and multimillion-dollar stadiums.

“This is an industry,” said Don Schumacher, executive director of the National Association of Sports Commissions in Cincinnati. “We’re not just talking about a few zealots around the country who like beach volleyball.”

Schumacher’s organization was founded in 1992 with 15 sporting commissions and authorities. Now there are more than 400 member organizations representing more than 350 cities competing for sports-travel events.

The most popular sports are soccer, basketball, baseball, softball and volleyball, but rugby and lacrosse events are making big gains. “Those sports weren’t even in view 10 years ago,” Schumacher said.

Beach tennis was not an organized sport in the United States 18 months ago. Marc Altheim happened upon the sport — which combines a beach volleyball court with the rules and scoring of tennis (without the bouncing) — in 2003 while vacationing in Aruba. By May 2005, the beach tennis tour had held its inaugural event in Charleston, S.C. This year, a truck filled with customized nets, racquets and balls and emblazoned with the Beach Tennis USA logo made its way across the country to introduce the sport to the West Coast.

Altheim and his team set up seven courts in Santa Monica, Calif., and Long Beach, Calif., and more than 750 people stopped by to take a whack. “In some places, people are more apt to stop and watch,” Altheim said. “In California, we couldn’t keep up with the waiting list of people who wanted to play.”

Altheim said he has been receiving more and more calls from interested host cities.

“Pretty much everybody we talk to about it wants us to do it,” he said. “The only problem is getting a permit. We are so new, they have to fit us under a category they don’t have.”

The Coney Island stop on the A.V.P. Crocs Tour brought 32 men’s teams and 32 women’s teams, a total of 128 players, which were expected to draw tens of thousands of fans.

Leonard Armato, commissioner of the A.V.P. tour, said the tour stops were selected based on corporate sponsors, community partners and facilities.

“We want to build flagship events,” he said. “We want people to be able to circle their calendars.”

He said cities were eager to hold the A.V.P. because it attracts the coveted 18-to-34-year-old demographic.

Buddy Wheeler, sports marketing coordinator for Virginia Beach, said traveling sports were spreading.

“Beach wrestling has taken off all of a sudden, and I got a group in Raleigh that was concerned because they didn’t have a beach,” Wheeler said. “But they can do the same thing. I don’t think it’s confined to beach communities.”

Many cities truck in sand to hold events typically reserved for coastal beach communities. Altheim’s beach tennis tour may make a stop in Milwaukee. “I don’t even know if Milwaukee has a beach,” Altheim said, “but we’re trying to meet their needs.”

Wheeler said he thought America’s appetite for sports was growing more diverse.

“It used to be the only thing on TV was baseball, basketball and football in season,” he said. “Now you flip around on cable and you see everything.”

The North American Sand Soccer Championships in Virginia Beach started in the early 1990’s with 26 teams. In 2006, it had more than 8,000 players on 739 teams.

“If you include all the players, their moms, dads, kids, wives and girlfriends, and you’ve got more than 25,000 people,” said Dick Whalen, the event’s executive director. “They bring their lawn chair and picnic basket or sit in the bleachers and see everything that’s going on and then go right back to what they were doing.”

Schumacher said several factors had contributed to the growth of participatory sporting events, including the desire of baby boomers to stay in shape while spending more time with their families.

And the smallest athletes produce the biggest payoffs. “The younger the athlete, the more people travel with the team,” Schumacher said. “And as far as the grand slam? Young female travelers. Daughters will produce grandma and grandpa, whereas a son most likely will not.”

A soccer team of about 18 players will easily generate 40 or 50 travelers, he said. “This is a business. It’s not just for fun. It’s very rewarding.”

Cities are most interested in events that fill hotel rooms, measuring success by the number of “room nights” they bring, said Schumacher, who is working on a report on what makes sports-travel events attractive to cities.

“The No. 1 reason communities are in the business is room nights,” he said. “Because if you get the room nights, visitors will spend money in other ways. You get the meals, the car rental, shopping and ancillary spending at a water park, a round of golf or a museum.”

National television exposure used to be a priority for cities, Schumacher said. “People used to say if you were hosting the Super Bowl, it was an honor,” he said. “But if you’re a Super Bowl city or an N.C.A.A. Final Four host, it’s not worth it if there aren’t people staying in your hotels.”

Marc Schreiber, vice president of marketing and development for the St. Louis Sports Commission, said that while the economic impact of an event was always a consideration, the top priority is finding events that excite St. Louis residents.

“If you’re bringing in things that people yawn about, you’re not doing it right,” Schreiber said.

Schreiber said the commission received credit for the events it attracted, “but we should get more credit for the events we don’t bring,” he said.

“There’s a whole host of things that get passed over as you evaluate what’s going to fit here and what isn’t,” he said. “It may not be a good fit financially, or it may not play as well here.”