Position Fixing with Neither Dead Reckoning nor GMT

Abstract

This is a short summary of a paper which shows what a navigator can do to fix his position at sea using basic equipment (sextant, hand-held compass, almanac, four-figure mathematical tables) without the help of dead reckoning or the benefits of GMT.To proceed from an almost complete absence of spatial and temporal data the navigator has to observe the sextant altitudes The GMT having been found, the navigator can easily deduce his longitude. With care the results for both the latitude and longitude can be obtained to the nearest minute of arc. The penalty for the almost complete ignorance of one's position and time is a great deal of numerical work which may be too demanding for navigators with only an O-level in mathematics.The present method is different in principle from the now obsolete lunar distance method which requires the measurements of the altitude of the Moon and one star, and the angular distance between them.Readers who are interested in this subject are invited to write to the author, care of the RIN for details.available at https://www.cambridge.org/core/terms. https://doi