Definition:Nautical Mile

Definition
The nautical mile is a unit of length which is used for air and sea navigation.

It was originally defined as the length measured along Earth's surface of one minute of latitude along a meridian.

It is now defined as exactly $1852$ metres.

Also defined as
Before $1929$, the nautical mile was defined as either:
 * $6080$ feet (what is now known as the British admiralty mile)
 * $6080 \cdotp 2$ feet (the American nautical mile)

Older textbooks may still refer to either of these now obsolete units as the nautical mile.

Also known as
Some sources refer to this unit as the international nautical mile.

Also see

 * Definition:Mile:
 * Definition:International Mile
 * Definition:Admiralty Mile