Astronavigation from Square One

Books for the leisure sailor on a difficult subject generally try to make it appear easy - with more or less success. If this was the intention here it has failed. The present reviewer has a good understanding of the subject but still found this book hard going. It is written more in the style of a scientific treatise, with frequent use of abstruse technical language, than a plain man's guide. Illustrations are of the most basic kind, simple line diagrams with no use of colour or shading, for example to show a view in three dimensions, and are in many cases not easy to follow. There are no photographs where these would have been useful eg to show the working parts of a sextant.

The quality of production is also fairly basic; overall it has something the feel of a PHD thesis. There are one or two significant howlers. The earth's daily rotation is slowing at a rate of about 2 milliseconds per 200 years, not 2 milliseconds per day (p 103). The 2 milliseconds per day is relative to the rate of the atomic clock, a different matter entirely (and the source of a common misconception). Sadly, because a lot of work has obviously gone into it and the author has admirably sought to explain the science behind the subject, it is not recommended. There are better, easier to assimilate, books on this subject. - BMF