A buoy is a floating device that is anchored to the ocean floor or secured to the shore. Synonyms for buoy include float, marker, beacon, signal, signal buoy, sea marker, and navigational aid. Each of these words conveys a slightly different meaning or context for the use of a buoy. For instance, a beacon may suggest a warning or signal of danger, while a signal buoy may be used specifically for transmitting messages. Whether used for maritime navigation or as a warning to swimmers, buoys are an essential element of water safety and protection.