Kailua brothers Patrick and Ryan Dolan have been hooked on flatwater kayaking nearly half their lives. They have come to accept the fact that waves rock the boat in their sport too.

The Dolans and their USA Canoe/Kayak teammates will be in Mexico City Tuesday for the Pan American Championships, which run Thursday through Sunday. A top-five finish qualifies a boat for next year’s Pan Am Games, the initial step in qualifying for the 2012 Olympics.

For the first time in their Olympic-dream lifetime, the brothers will not be in a boat together .

"It’s kind of a bummer because we always wanted to paddle together," says Ryan, the younger Dolan by 18 months. "We’re at a point now where we’ve both got to find and do whatever we need to do to make it. Use our strength."

His 22-year-old brother calls Ryan an "anaerobic machine, a full-on sprinter." Patrick is the endurance part of the Dolan paddling package. In Mexico City he will be in two 1,000-meter races — the K-4, and K-2 with Morgan House. Ryan is going the new 200-meter distance alone and with Tim Hornsby. He is also racing K-1 500 for the first time internationally.

When Brandon Woods left the program and the Americans’ K-4 boat hit rough waters just before World Championships in Poland in August, the fallout helped Ryan find himself.

"I made a humongous improvement in the 200 (this year) and raced some K-1 200 in World Cups and did OK (13th overall), so I started to realize more and more that I was better at 200 meters than 1,000," he said. "I found out the hard way during the 1,000 meters in Poland. I was stroking the K-2 with Pat and just falling apart at 500 meters or 700 meters because the way I paddle is better for sprinting."

Ryan described it as "the lights just turned on" and Team USA coach Guy Wilding noticed immediately. He began to groom Ryan for shorter races, splitting up the Maryknoll graduates.

"It was kind of a bummer it had to happen at that event, but better now than later," Ryan says. "This next year is the (Olympic) qualifier. … I’m pretty much gearing up this year for sprints because I feel like it’s my best chance to make the Games this time around."

Ryan views the "breakup" with his brother as doing "what’s best for each other" and is beginning to grow fond of the independence of K-1.

"A lot less can go wrong and if it does go wrong it’s all on you," he said.

Patrick has not given up all hope of racing with his brother.

After Mexico, he is looking forward to "much-needed rest" from twice-a-day, six-days-a-week training. His "rest" includes ocean paddling and lots of weight training. He is intent on improving his speed so he might be able to race 200 meters with his brother.

But first, there is Mexico City — an event that wasn’t originally on Team USA’s schedule — and the 7,000-foot altitude that presents its own challenge. For sprinters, it is not that big a deal, but for those in 1,000-meter races there is little coaches can do at this late stage. The Americans could not afford to go to Mexico early and acclimate.

Patrick ruefully remembers his first race in Mexico as a junior four years ago.

"I was the first person to race for the U.S. team and it was the K-1 1,000-meter junior final," he said. "At 500 meters I started building lactic acid. I felt like I was limping down the course.

"I finished and barfed my brains out. I know what to expect. It’s going to hurt. Guy and our physiologist keep telling us altitude never killed anyone, so toughen up."