Currents are best described as rivers or streams within a larger body of water. In the ocean, currents are formed by winds, waves, tides, and the rotation of the earth.

The largest currents in the ocean are offshore standing currents, which are a major factor in water temperature. For example, currents off the West Coast of the United States primarily move from the north to the south, which means the waters are chilled by the cold, northern waters. On the East Coast, currents move from the south to the north, which significantly increases the water temperatures.

As divers, we are more concerned about the currents that are present near the shore. These include longshore, rip, and tidal currents.