International Nautical Mile PDF

Dpartment of Navigation - 18 - Costal Navigation (1) C-Sailing for a long period north or south of the equator 8-* defines 'international nautical mile', 'cable' and 'knot' A) The International Nautical Mile: The International Nautical Mile is a standard fixed length of 1...

Dpartment of Navigation - 18 - Costal Navigation (1) C-Sailing for a long period north or south of the equator 8-* defines 'international nautical mile', 'cable' and 'knot' A) The International Nautical Mile: The International Nautical Mile is a standard fixed length of 1852 m. Its abbreviation is the term "n mile" (or "n. mile" or "nm") B) Cable: One/tenth of a Sea Mile which varies between 184.3 m and 186.2 m according to Latitude. A Cable thus approximates to 182.88 m C) The Knot: The fixed or standard unit for measuring speed is called a Knot, and equals one International Nautical Mile (1852 m) per hour. Its abbreviation is the term "kn" (NOT "kt"). D) The Sea Mile: The Sea Mile is the length of one minute of arc (1') measured along the Meridian in the Latitude of the position. On Admiralty charts on the Mercator projection, the Latitude graduations form a Scale of Sea Mile, and the symbol 'M' used to represent the Sea Mile which represents a minute of arc E) Length of the Sea Mile: The Radius of Curvature in the Meridian increases as M value moves from the Equator to the Pole; thus, the distance subtended by l' of arc also increases. The length of the Sea Mile is shortest at the Equator (1842.9 m) and longest at the Poles (1861.6 m), with a mean value of 1852.2 m at 45˚ Latitude (at WGS 84)