The 13th edition of this bestselling book is proof of the success of Mary Blewitt's concise and clear style in explaining a particularly difficult skill, and it has been the bible for many generations of ocean navigators.

Since this book was first published, the huge advances in electronic navigation have transported most offshore navigators to a world of press-button convenience. However, there is still a vital need for traditional skills when things go wrong: batteries can fail, aerials go overboard, and electronics have been known to get wet.

A bestseller for over 65 years, Celestial Navigation for Yachtsmen is a model of simplicity and clarity. The worked examples require only straightforward addition and subtraction, which explains why this book has truly earned its reputation for admirable conciseness and for making a tricky subject easy to understand.

This edition has been thoroughly revised by Andy Du Port, the highly respected ex-editor of Reeds Almanacs.

'The "bible" of navigation for generations of yachtsmen... worth its weight in gold' Sailing