Wind, the Coriolis effect, variations in temperature and salinity, and other forces acting upon the water create an ocean current, which is a continuous, directed movement of seawater. The majority of ocean currents are horizontal water movements. Tidal currents come from the tides, while surface currents come from the wind and waves.

Because they move in time with the tide, tidal currents are quasiperiodic; associated with the pull that the moon and sun exert on the water in the ocean. In certain locations, particularly around headlands, tidal currents can form a variety of complicated patterns. Winds and changes in water density cause non-periodic or non-tidal currents to form. In littoral zones, breaking waves are so extreme and the profundity estimation so low, that sea flows arrive at frequently 1 to 2 bunches.

Surface currents, also known as “drift currents,” are created by the wind and waves. Under the influence of rapid wave movement (which varies on timescales of a few seconds), these currents can decompose into one quasi-permanent current (which varies on an hourly basis) and one Stokes drift. Wave breaking and surface wind friction, which has a smaller governing effect, both accelerate the quasi-permanent current.