Motion in the ocean is a term used to describe the movement of water in the ocean, which is caused by a variety of factors. Tides are one of the most important factors that affect the motion of the ocean. Tides are the regular rise and fall of the sea level due to the gravitational pull of the moon and sun. The gravitational pull of the moon is stronger than that of the sun, so the moon has a greater influence on the tides. Tides occur twice a day and can be predicted with accuracy. The height of the TIDE also varies depending on the location and time of year.