Mile two points on the navigational chart, then place the open dividers against the minutes-of-latitude scale at the edge of the chart, and read off the distance in nautical miles. The Earth is not perfectly spherical but an oblate spheroid, so the length of a minute of latitude increases by 1% from the equator to the poles. Using the WGS84 ellipsoid, the commonly accepted Earth model for many purposes today, one minute of latitude at the WGS84 equator is 6,046 feet and at the poles is 6,107.5 feet. The average is about 6,076 feet (about 1,852 metres or 1.15 statute miles).
Adlard Coles Nautical Adlard Coles Nautical Adlard Coles Nautical is a nautical publisher, with over 300 books in print. The company publishes books on topics of interest to sailors and motorboaters and also ‘landlubbers’ with an interest in the sea. Their list includes almanacs, cruising guides, pilot books and how-to instruction books, as well as large format photographic books, sailing narratives and sea-related reference, maritime history, humour and trivia books. Adlard Coles Nautical has been part of Bloomsbury Publishing since 2003. The company was founded by yachtsman Kaines Adlard Coles in 1947. He wrote many of the books, including pilots, sailing narratives and