Last week, about five hundred paddlers raced their canoes and kayaks on the Connecticut River. They converged at the Dartmouth Boathouse in Hanover for the United States Canoe Association ?2002 Marathon Canoe and Kayak National Championship?. Over four days, competitors of all ages paddled up and down 13 miles of the river. NHPR?s David Darman spent a day at the races, and filed this report.