Celestial Navigation for Yachtsmen

Celestial navigation, like knots and splices and reading maritime charts and tide tables, is one of the essential sailing skills. Whether you are a daysailer, weekender, blue water cruiser or lone circumnavigator, there WILL come a time when the GPS quits, the Loran won't work, and you're going to say, "Where the & $@!* am I?". If you haven't learned celestial nav at that point you had better be a real quick study or have hired a good estate planning lawyer. But assuming that Clarence Darrow Dershowitz Kunstler Belli Nizer, Esq. isn't in your crew, Mary Blewitt's book is a good thing to have. Brief, concise, and Ptolemaically simple to understand, Blewitt takes the hocus-pocus out of asking the heavens for directions. The difficulty with learning celestial nav isn't so much the math (as most people want to believe) as it is that modern man is SO far out of touch with the natural world that looking at the night sky is like looking at---something dark and mysterious. However, add a few very basic, easy-to-grasp concepts to your skill set and your Sunfish will suddenly become the Santa Maria. Knowing celestial navigation will help you to sail anywhere and, even better, to know where you are when you get there. To that end, this book is an invaluable learning tool.

Before crossing the Atlantic in 1978 on my 22' sailboat, I read many books on celestial navigation and became convinced that it was an inpenetrable subject and then, on reflection, I realized that that could not be so as so many navigators had had less geometry etc than me. I figured the authors did not really know what they were talking about. And then I came across Prof. Blewett at the Boston Museum of Science, teaching on 10 Wednesday evenings. After the first lecture, on the noon sight, she said, if you your boat is going faster than 20 kts then you don't have to come back for more. That is all you need. She was absolutely right. But I did continue -- I took the course so I could do the fun-and-games of star sights too. I can now teach her course in 45 minutes.

I was concerned that such a small book (just over 100 pages) could contain enough information about celestial navigation to make my sextant useful. I shouldn't have been. The book is bypasses hype, lore and commentary and deals strickly with the topic at hand. It can be tough going but the book is written clearly enough so as not to be confusing on such the subject.

I thought it was going to take years to learn celestial navigation. After reading Celestial Navigation for Yachtsmen I was plotting my position within miles of my known position in just a few days (I was using a plastic sextant Mark 15). The first 22 pages of reading requires a lot of thought and time to absorb the information but after one understands the main concepts the rest of the book becomes easier to follow. I highly recommend this book.

Having struggled with the arcane mechanics of celestial navigation for the past three years it was an immense relief to discover a tome that could lead me through both theory and practise in less than 80 pages! Ms. Blewitt's matter of fact approach to the complexities of sun and star sight reduction etc. is refreshing indeed. For anyone contemplating offshore navigation of any type, this book is worth a dozen night school courses.