Navigational buoys along the Maine coast, Portland, Maine Marine bells and clappers. The bell is fixed and the motion of the buoy moves the clapper to make the sound. The bells are made of brass or bronze depending on how old they are and can weigh as much as a couple hundred pounds. The buoys are set to mark navigable channels and to alert boaters to hidden hazards. Both the visual and audible signals are critical to the safe navigation of vessels, from large tanker ships to fishing and recreational crafts. Although most boaters use electronic navigation devices these days, boaters still watch for the buoys and listen for the sounds in order to help them navigate safely. |