Lake Calhoun is a choppy mess, little swells and whitecaps whipping up as windsurfers drift by in the breeze. I'm standing on the water, legs spread, feet solid on the deck of a surfboard.

Sunlight cuts through green water, seaweed gliding by beneath. My hands grip a paddle for propulsion, long reaches and pulls moving my upright frame through the wind, away from shore.

"You got it!" shouts Tara Krolczyk, owner of LakeSUP, a Minnetonka-based surfboard reseller. "As easy as standing on a sidewalk."

It is a Wednesday evening in mid-July, and I've come to try a sport new to the Midwest. Stand-up paddle-surfing has roots in Hawaii, where the discipline was created decades ago as a means of flat-water transportation. Over the past three summers, stand-up paddling -- SUP, for short -- has sent waves through the surf industry.

"SUP is probably the fastest-growing current trend in surfing," said Sean Smith, executive director of the Surf Industry Manufacturers Association in Aliso Viejo, Calif.

Smith attributes the sport's popularity to its versatility. It can be done when there are good waves or no waves at all. It's also great exercise, he said.

Further bolstering the sport, surf stars such as Laird Hamilton and Dave Kalama have embraced SUP. ESPN recently reported that World Cup skier Julia Mancuso cross-trains standing up on a surfboard.

Hollywood types including Matt Damon, Jennifer Garner and Pierce Brosnan have been caught on camera SUPing, drawing populist fuel to the fire.

SUP scene in Minnesota

Krolczyk formed LakeSUP in May after a family vacation to Florida. A former professional dancer and Radio City Rockette, Krolczyk, 38, fell in love with SUP after just two hours on a rental board off Key Largo.

"It was an amazing core workout," she said.

LakeSUP sells stand-up surfboards and paddles on its website (www.lakesup.com). Krolczyk runs free monthly demonstration clinics on area lakes and travels to give private lessons.

For the first time this summer, two Twin Cities businesses -- Excel Boat Club on Lake Minnetonka and Wheel Fun Rentals at Lake Calhoun in Minneapolis -- rent SUP boards. Loaner boards start at $15 per hour at Excel Boat Club, where surfers push off on tours of St. Albans Bay or to Big Island on the main lake beyond.

A few Minnesotans have bought boards, including Jesse Daun, 34, an engineer from Minneapolis.

"I was wanting a canoe or kayak for the summer, but they wouldn't fit in my apartment," he said.

Instead, Daun bought an 11-foot inflatable SUP board from a distributor in Hawaii. He blows it up on the shore of Lake of the Isles near his Uptown apartment, then paddles off for hourlong workouts, thousands of strokes and up to 6 miles at a time.

Daun, a marathon runner as well as a self-described "nature guy," said he loves the view: "Standing up you can see ahead and down into the water where there are minnows, bass and snapping turtles."

Getting some board time

At the LakeSUP demo in July, I joined a dozen surfers trying the sport for the first time.

Dean Rizer, 66, of Minneapolis, appeared to be walking on the water, his board half-obscured by waves, as a crowd gathered to watch.

"What is that?" someone shouted. "Can I try?"

Krolczyk said funny looks are part of the experience.

"We get a lot of attention," she noted.

My session began with a wade into waist-deep water. I put my hands on the center of the board and hopped on, the platform wobbling some but supporting my weight with an immense buoyancy.

"Reach and pull," Krolczyk shouted as I drifted away.

The chop bit at the nose of the board, a slight turbulence with waves rolling onto the deck, washing my toes. But the board -- 11 feet long and nearly 3 feet wide -- floated steady as a pontoon.

Standing up and reaching with a paddle blade digging in and pulling deep, a SUPer can generate more power than a kayaker sitting down. Indeed, in five minutes, paddling while staring straight ahead, I could skim nearly to the center of the lake.

The board spins with a backstroke, a couple dips rotating the deck 180 degrees. Out from the beach on Calhoun, windsurfers coursing by, I was comfortable controlling the craft after just a few minutes.

But near the shore I found my board's tipping point. Playing around, walking on the deck and paddling from new positions dipped the board's edge underwater, my feet zinging off, paddle flying.

Then I popped up, my board drifting away. I found my paddle and swam, pulling back on deck, replanting my feet.

I stood up and paddled. Krolczyk was skimming ahead, her frame a silhouette on sky with a setting sun. I reached and pulled, the board gliding easy, spinning and tracking away, one last SUP before the sun went down.

Stephen Regenold is a Twin Cities writer and author of the syndicated column www.thegearjunkie.com.