See Equatorial Countercurrent. The highest point in a propagating or standing wave. See high water and tidal wave. Currents may be classified as tidal and nontidal. Tidal currents are caused by gravitational interactions between the Sun, Moon, and Earth and are part of the same general movement of the sea that is manifested in the vertical rise and fall, called tide.
Tidal currents are periodic with a net velocity of zero over the particular tidal cycle.
See tidal wave. Nontidal currents include the permanent currents in the general circulatory systems of the sea as well as temporary currents arising from more pronounced meteorological variability. Current, however, is also the British equivalent of our nontidal current. See total current. Tidal current relations that remain practically constant for any particular locality.