The term of ocean motion refers to the movement of the ocean's water, which is largely driven by the gravitational pull of the moon and sun. TIDAL is a five-letter word that describes the regular rise and fall of the ocean's surface due to the gravitational pull of the moon and sun. This phenomenon is known as the TIDAL cycle and it occurs twice a day. The TIDAL cycle is responsible for the formation of tides, which are the regular changes in the sea level.