Nautical Astronomy. Astronomy as applied to navigation.
Nautical Day. Day, formerly used at sea, commencing with Sun's noon transit. Abolished in Merchant Navy, January 1, 1925, but abolished in Royal Navy several years before. Nautical Distance. Length of rhumb line intercepted by two positions.
Nautical Mile. Length of arc of F of meridian in latitude of position of measurement. Value varies between 6046.4 ft. in Equator and 6107.8 ft. at Poles. A standard of 6080 ft. (1853.18 m), correct for Lat. 48°, is used in log registrations and practical navigation. The International Nautical Mile = 1852 metres, correct for Lat. 44 ½ °. Sea Mile. Nautical School. Educational establishment in which navigation, seamanship and other subjects connected with shipping are I taught.