Attendees of the Outdoor Retailer Show view the camping tent display area of the event in front of the Salt Palace Convention Center on Wednesday, Aug. 5, 2015, in Salt Lake City. There has been discussion of moving the twice a year event from it's long time home in Salt Lake City. (AP Photo/Kim Raff)

SALT LAKE CITY - Colorful paddleboards and pictures of people practicing the sport in beautiful settings fill the exhibit halls at the world's largest outdoor retail trade show this week in Salt Lake City in the latest illustration of the sport's exploding popularity.

They make long, skinny boards for racers. There make wide, sturdy ones for more casual users, some of whom do yoga or fish off the boards. They even make inflatable boards for people who want the convenience to be able to roll them up and put them in a bag.

Once viewed as a fringe activity or fad, paddle boarding is now carving out an expanding place in the lucrative outdoor recreation industry. A growing number of companies are doing a brisk business selling boards, paddles and accessories to accommodate the growing popularity.

Whether in oceans on the coasts or inland lakes and rivers, people are increasingly drawn to a sport that can be done for vigorous exercise and racing or for casual paddling or yoga with friends and even dogs aboard.

Participation in stand up paddling in the United States has increased nearly three-fold from 2010 to 2014, according to a study from the Outdoor Foundation. That makes it one of the fastest-growing outdoor sports, the foundation says.

Last year, an estimated 2.7 million people participated in the sport, up from about 1 million in 2010, the first year the foundation began including the sport in its annual survey. The participation numbers put it on par with surfing and BMX bicycling.

The sport is easy to learn — unlike other board sports like surfing, wind surfing and snowboarding — and can be practiced all around the world, said Jimmy Blakeney, marketing manager at of Bic SUP, one of the leading companies making boards.

And there's what Blakeney calls the "cool factor" that also draws people.

"You're standing up, you're in your bikini, you're being seen," Blakeney said. "Boards are cool. A lot of young people really like being on a board versus a boat."

The roots of modern paddle boarding are traced to Hawaii, where surfers used paddles to get out further or do exercise when there were no waves. The sport slowly spread from Hawaii and has been around in the United States for about 10 years, Blakeney said.

Growth really accelerated about five years ago, he said. Companies not only sell to outdoor shops, but to rental companies, which say they do well renting the boards for people who want to try them for the first time.

The Stand Up Paddle Industry Association formed in 2012 to bring cohesion and support for manufacturers, retailers and people who teach, train and organize races.

Kristin Thomas, the industry association's executive director, said the versatility of the boards is a huge draw. "It's very easy to use on one level and yet can be as extreme as you want it to be. People are surfing huge waves. They are doing whitewater," Thomas said.

As a burgeoning sport, the industry is trying to establish best safety practices and manage different rules being established. For instance, there is still debate about whether paddle boarders should wear life jackets or have the boards harnessed to their ankles, like surfers.

The U.S. Coast Guard recently designated paddleboards as a vessel, like a canoe or kayak, meaning users must have a life jacket and sound-making device aboard unless they are within a swimming, surfing or bathing area.

A 21-year-old Utah man recently died while paddle boarding on a mountain lake when winds came up and he went missing, authorities said. He wasn't wearing a life jacket, they said.

Prices for boards range from $400 to $2,000-plus. Paddles cost from $75 to $100. As is the case with any sport's equipment, you have to pay more for lighter, higher-performing boards. Bic SUP's top seller is one that retails for about $1,000, Blakeney said.

"We always say: light, durable, affordable: pick two," Blakeney said.

The majority of the people are recreational users who use the boards about 10 times a year, he said. A smaller portion of people, often the types who are drawn to running and triathlons, use the boards for vigorous exercise and compete in a growing racing circuit, Blakeney said. The World Paddle Association formed in 2010 to oversee the sport.

The growth of the sport was also on display this week in Utah at a demo day for the Outdoor Retailer Show at a reservoir north of Salt Lake City. Paddle boards filled the lake, a stark contrast from the late 2000s when only a few companies were catering to the sport, said Jeff Atler, president of Hobie.

"Now, they are on every body of water worldwide," Atler said. "It's simple, it's enjoyable and you can do it on just about any body of water."

News from © The Associated Press, 2015