The speed of ocean currents is commonly measured in knots. Knots are the standard unit for expressing the speed of ocean currents and are widely used in navigation and marine science. A nautical mile(knot) is slightly longer than a regular (statute) mile, with 1 nautical mile being approximately 1.1508 statute miles.
In oceanography, particularly when using scientific instruments like current meters or ADCPs (Acoustic Doppler Current Profilers), ocean currents may be measured and reported in meters per second.