Disturbance of the ocean’s surface, seen as an alternate rise and fall of the surface. Ocean waves are of several types: (a) wind-generated waves, e.g. sea waves (chaotic wave pattern) and swell (long-period waves); (b) catastrophic waves, e.g. tsunamis, landslide surges, and storm surges; and (c) internal waves (subsurface waves at the boundary between two water layers).