my depth finder/gps, a humminbird 363, would not read depth in water less than 5 ft. yesterday. i have a trolling motor transducer. what's funny is i lifted the trolling motor up as far as it will go, still nothing. i dropped the trolling motor back down and pulled on the rope, bringing it up 6 inches or so, and it read ok. anyone ever experince this problem? we tried changing angles on the trans., still did not work. works fine in water over 6 ft. deep.