WINONA, Minn. —Fire Department rescuers threw a line to a Mississippi River boater whose propeller had become entangled in a rope. The boat, powerless, was drifting down the main channel after dark. Rescuers pulled the boat into the St. Charles Street landing.  The boater, Timothy Lee Peterson, age 45, of Winona, was unhurt. Police, however, took him into custody as boating while impaired. Officers said Peterson smelled of alcohol and behaved drunkenly: Slurred speech and poor balance. A breath test to measure the alcohol in his system wasn’t possible, police said. Instead blood was drawn and sent to an outside lab for testing to determine whether to recommend elevated charges to the county prosecutor.