ON THE MISSISSIPPI RIVER - Jim Kennedy watches the river like a hawk. From his view 33 feet up in the pilot house, Kennedy stares out wide windows at blackened driftwood, eddies, even sometimes rambunctious yachters steaming up the wide, blue waters of the Mississippi River near St. Paul. "They're about the worst kind," Kennedy said, on the Tuesday after Labor Day. "Drunk yachters. But they ...