A sport from the past is fast becoming a sport of the future.

The proof came yesterday at Kuhio Beach, Waikiki, where 24 competitors participated in the opening rounds of the C4 Waterman/Honolua Surf Co. Stand-up Paddle Surfing Invitational.

"This sport is still growing — we haven't even scratched the surface yet," said competitor Todd Bradley. "Who knows how big this sport will be years from now, because who knew we'd be able to have a contest like this?"

Stand-up paddle surfing was started by some of the Waikiki Beachboys in the 1960s. It was revived around three years ago, and is now the latest craze in ocean sports.

The sport involves a large surfboard and a canoe-style paddle. The surfer stands on the board and uses the paddle to stroke into waves (as opposed to lying down and arm-paddling for waves like regular surfing).

"I'm an enthusiast of the sea, and I do a lot of different sports, but I've really taken to stand-up paddle surfing in the last two years," competitor Leleo Kinimaka said. "It's just a whole new way of surfing when you have a paddle in your hand."

This week's contest is part of the Duke's OceanFest. This is the first year that a stand-up paddle surfing contest is part of the OceanFest, which has been held every year since 2002 in honor of Duke Kahanamoku.

"Duke was the greatest waterman, and this is the birthplace of the sport, so we really wanted to be a part of it," Bradley said.

Bradley, Mike Fox and Brian Keaulana are the founders of C4 Waterman — an "ocean lifestyle" company that focuses on stand-up paddle surfing.

"We want to support the sport and perpetuate it," Bradley said. "Instead of just being a recreational sport here, we'd like to share it with the world, and one of the ways to get word out is through contests."

Prizes will be awarded to the top performers, but no prize money. C4 Waterman and Hono-lua Surf Co. paid for the entry fees for all 24 invited competitors.

"Originally, we wanted to invite 16," Bradley said. "But so many guys are doing it now, and so many of them are good at it, we had a hard time even getting it to 24."

Tiare Lawrence from Palolo was the only female to receive an invitation. She has been stand-up paddle surfing for three years.

"Being a canoe paddler and a surfer, as soon as I tried this sport, I was hooked," she said. "It's like you get the best of both worlds."

The advantage of stand-up paddle surfing over regular surfing is the viewpoint and the use of the paddle.

"You're standing up on the board, so you can see things you've never seen before," Kinimaka said. "And you can utilize your paddle as a balancing stick ... you can get into parts of the wave that you normally wouldn't be able to without a paddle."

The advantage of stand-up paddle surfing over canoe paddling is the full-body workout.

"(Canoe) paddling is great for your upper body," Lawrence said. "But with stand-up paddling, you get the whole package. You work your legs, your abs, your upper body, everything."

Still, it is not as easy as it sounds.

"When you first start, it's really hard to balance," Lawrence said. "But the good thing is you don't have to go straight into the surf. You can take the board and just paddle around in the flat water to get a feel for it, and even that is fun."

Bradley said the sport may still be years away from reaching full professional status, but at least it is riding a wave of momentum.

Kinimaka, for example, could already be considered a semi-professional competitor. He resides in Kailua, Kona, and said sponsors help pay for his trips to O'ahu for contests.

"This sport has evolved dramatically in the last year," he said. "I know it's going to keep growing and it's not going to go away."

The contest ran through the semifinal heats yesterday. Competitors advancing to Saturday's final were Dave Parmenter, Alika Willis, Noah Shimabukuro, Kalani Vierra, Bonga Perkins and Titus Kinimaka.

The OceanFest will continue today at Kuhio Beach with competition in the Roxy Jam Hono-lulu women's longboard surfing contest, and the World Title of Tandem Surfing contest.

The tandem surfing contest ran trials heats yesterday. California's Ryan Reynolds and Jennifer Jacquez won the trials final to earn a spot in the main event.

Also yesterday, Hawai'i competitors Bear Woznick and Krystl Apeles won the masters division of the tandem surfing competition.

Reach Dayton Morinaga at dmorinaga@honoluluadvertiser.com.