Most of the ocean currents are directly affected by the Coriolis effect, which states that the curving moves in two different paths due to the rotation of Earth's rotation.
The movement of the ocean currents are then affected by the continent landmass as the global winds and the Coriolis effect, most of the ocean currents move in a different direction than they actually are because they are deflected off of the continents. An example is the Benguela cold current.