Also, look at:	Nautical mile (nm) A nautical mile is a unit of length.  The nautical mile is used around the world for maritime and aviation purposes.  The international standard definition is: 1 nautical mile = 1852 metres exactly.  There is no official international standard symbol for the unit nautical mile. The symbols NM, nm and nmi are commonly used.			related sites
Sidenote In yachting the nautical mile is related to the speed a vessel can reach, whereas 1 knot = 1 nm per hour.