There is a light chop on Biscayne Bay as John Ruf checks his mainsail from the snug-fitting cockpit of his boat.

With his head just visible in the low-lying boat, he jockeys for position at the start of the Rolex Miami Olympic Classes Regatta, a five-day, 15-race event.

Ruf finishes the third race of the day and is exhausted. He heads the half-mile back to port. Using his upper body, he pushes himself onto the dock and rolls onto a padded cushion toward his wheelchair.

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Ruf will represent the United States in the 2.4-meter class at the Paralympics in China this summer, having won last fall's trials. The 39-year-old sailor is expected to challenge France's Damien Seguin, the 2004 champion, for the gold medal. He finished eighth in Miami, competing against both able-bodied and disabled sailors.

"The thing I like most about sailing is that the wheelchair stays on the dock," Ruf said. "There's an amazing amount of freedom that comes with that. "

Betsy Alison, coach of the U.S. disabled sailing team, said Ruf is "very laid-back, low key" but that masks his inner strength.

"He has overcome significant obstacles," she said. "When he sets his mind to do something he does it 100 percent."

Ruf has been sailing since he was a boy growing up on Wisconsin's Pewaukee Lake, learning from his mother and grandfather even though he had a spinal tumor that forced him to walk with a cane or crutches.

He started with the X-boat then moved on to the M-16 scow, and ultimately a 28-foot E scow, a high-performance boat his great grandfather Arnold Meyer Sr. helped design in the early 1920s.

When complications from a 1998 auto accident left him paralyzed from the waist down he switched to the 2.4 meter boat in 2000.

"I really wanted to sail," he said. "From Day One, I've always focused on what I can do and not on what I can't do. So, I just said I can do this, and it's been a pretty cool adventure."

But that left Ruf, accustomed to sailing with a crew, alone in a wet boat that's just under 14 feet long — about the size of a kayak. Ruf says it's "like sailing in the bathtub with the shower on."

And it's slow, compared to the E scow, but it was an easy trade-off.

"No matter how much I love the E scow, I'm never going to win a gold medal in the E scow," he said.

The Miami regatta offered the perfect opportunity to measure himself against many of the same boats that will compete in China.

A rigorous training schedule lies ahead, starting with several weeks of training in Clearwater with his coach Marko Dahlberg of Finland, a two-time world champion in the 2.4. In May, he will compete in a regatta in China, followed by competitions in Europe.

Back at the Miami dock, Ruf put his head back, smiling at the sun. He tells himself that the Paralympics is just another regatta. And, always, remember the basics: have some options and sail fast.