The classic How to Read a Nautical Chart explains every aspect of electronic and paper nautical charts: how a chart is assembled, how to gauge the accuracy of chart data, how to read charts created by other governments, how to use information such as scale, projection technique and datum that every chart contains; how not to get fooled or run aground by overzooming. Nigel Calder teaches you how to squeeze every ounce of information out of a nautical chart (on your GPS, chartplotter, or nav station) and understand the limits of accuracy for all charts, paper and electronic, raster and vector