The Practical Guide to Celestial Navigation BookThe practical guide to celestial navigation know what to do step by step, understand why you're doing it, and be confident that you can put it into practice when on board. Did you know that a person standing on the equator is effectively travelling at 900mph? And did you know that you can use this information to work out where you are in the world, to an accuracy of about 3 or 4 miles? No GPS, no computers. Just a sextant, some tables from an Almanac