Wave base

[1] In seawater, the water particles are moved in a circular orbital motion when a wave passes.

The radius of the circle of motion for any given water molecule decreases exponentially with increasing depth.

In the same pool, a wave with a wavelength of 0.5 metres (1.6 ft) would not be able to cause water movement on the bottom.

The portion of the seafloor that is only agitated by storm-driven wave action is known as the Lower shoreface.

Note that another classification exists, which considers that the zone affected by both fair weather and storm waves is to be defined as shoreface, whereas Upper offshore is the name given to the zone only affected by storm waves and Lower offshore a zone not disturbed by any surface wave.