GPS Backup with a Mark 3 Sextant: All Instructions and Tables Included; For Any Ocean, on Any Date; No Background in Celestial Navigation Required. Burch DavidPaperback

No power, and batteries used up? Alternatively, if you want to learn a basic celestial navigation position fix for any reason with minimum investment, this book shows how to do that.It's a short book, mostly tables. This book and an inexpensive Mark 3 sextant lets you carry on.

We wanted a solution that is compact and inexpensive, using tables and procedures that are easy to learn and use. You can read it in an hour or two, master the sights in less than that, and find your position the next time you see the noonday sun.Our guiding principle for this booklet was to provide a means of learning and executing a position fix at sea when a vessel has lost its GPS navigation. This goal led to our proposing a minimum kit that mariners would not hesitate to add to their gear to cover the unlikely situation it would actually be needed.

Mariners who cross oceans in small boats