Mile, Nautical

1 nautical mile = 1,852 m exactly, fixed by the First International Extraordinary Hydrographic Conference (Monaco, 1929) and recognized by the BIPM. It approximates one minute of arc of latitude along a meridian, so a degree of latitude spans about 60 nautical miles. Speed at sea is the nautical mile per hour, the knot. The old UK Admiralty mile of 6,080 ft (1,853.18 m) and the US mile of 1,853.248 m were both retired in favor of the international value.