The term air mile, also known as a nautical mile, refers to the distance between two locations.
The term knot, in reference to currents, is defined as one nautical mile per hour and is used to measure speed.
The term knot is defined as one nautical mile per hour.
British Dictionary definitions for nautical mile
Also called international nautical mile, air mile. a unit of length, used esp in navigation, equivalent to the average length of a minute of latitude, and corresponding to a latitude of 45°, i.e. 1852 m (6076.12 ft)
a former British unit of length equal to 1853.18 m (6080 ft), which was replaced by the international nautical mile in 1970 Former name geographical mile Compare sea mile