A foghorn is an audible warning traditionally associated with coastlines, harbors, lighthouses, and vessels operating in reduced visibility. Its low pitch and sustained volume help the signal carry across water and through fog. Online, recordings and imitations of these horns are commonly used beyond maritime footage, where their immense scale makes ordinary moments feel ominous or deliberately ridiculous. The sound remains useful because viewers recognize its warning quality immediately, even when it appears in a completely unexpected visual setting.