A breaking wave where the crest slides down the face of the wave is known as what?

A breaking wave in which the crest slides down the face of the wave is referred to as a spilling wave. This type of wave forms when the water at the crest moves forward and spills over the front face as the wave breaks. This occurs when the slope of the seabed is gentle, allowing for a gradual breaking motion. As the wave approaches shallow water, the crest cannot maintain its shape, leading to the characteristic spilling effect.

Spilling waves are commonly observed on beaches with gentle slopes, where the energy of the wave dissipates more gradually as it breaks. This phenomenon contributes to the formation of whitecaps and foamy water, creating a visually distinctive appearance as the water froths and pours down the wave face. The process is generally less violent compared to other types of breaking waves, such as plunging waves, where the crest dives sharply downwards, and surging waves, which do not break in the same way. Understanding this process is essential for recognizing various wave types and their impacts on coastal environments.