Bill Tannahill saw firsthand how glowing solar lights placed atop hazard markers in Lake Lanier helped him and his family find the way home on a very dark night. “Not that these lights are for navigation, but I could clearly see where I needed to go,” said the Forsyth County man and chairman of Lake Lanier Association’s solar lights committee. The Gainesville-based association has placed 123 lights on the lake, south of Browns Bridge, since the program started in 2013.