Oceanic current which flows in an east–west direction in the equatorial regions of all the oceans. The broad (1000–5000km) westward-flowing currents (North and South equatorial currents) are separated by a comparatively narrow westward-flowing countercurrent (the Equatorial countercurrent). The flow tends to be limited to the upper 500 m of the water column and the velocity is 0.25–1.0 m/s. The strength and position of the equatorial currents are controlled by the overlying wind system.