Kennedy is also a whitewater Kayaker. His father introduced him and his siblings to whitewater kayaking during early trips down the Green and Yampa Rivers in Utah and Colorado, the Columbia River, the Middle Fork Salmon in Idaho, and the Upper Hudson Gorge. From 1976 to 1981, Kennedy was a partner and guide at a white water company, "Utopian," based in West Forks, Maine. He organized and led several "first-descent" white-water expeditions to Latin America including three to hitherto unexplored rivers: the Apurimac, Peru, in 1975; the Atrato, Colombia, in 1979; and the Caroni,Venezuela, in 1982. He made an early descent of Great Whale River in Northern Quebec, in 1993, and has made many trips to Patagonia, Chile to run the Biobío River, the Futaleufú and other whitewater rivers.