And all I ask is a tall ship and a star to steer her by

--John Masefield--


One of the most beautiful and oft-quoted lines ever penned about sailing and the sea...

It also raises questions for most modern readers: "Just how do they steer by a star?" And more generally: "How are they able to find their position at sea that way?"

To begin, let us first answer: "They don't." Not in modern times, anyway. The universal use of highly accurate and reliable "real-time" electronics has relegated celestial navigation, as sailing by the stars is properly known, to one of those natty, romantic, but impractical Arts of the Sailor, like fancy knot-tying, building model ships in bottles, or indeed, sailing itself. Celestial is regarded as a useful but cumbersome emergency back-up system.

It is for those natty, romantic, but impractical people who enjoy having a very special legacy from our forefathers that this page is intended.


Introductory Questions and Answers

Is it hard to do?

Not really. "Tedious" would be a better word than "hard" to describe the work of celestial navigation. The work is detailed and lengthy, with answers coming slowly. But anyone who can understand high school algebra and trigonometry can feel comfortable with only a little practice. It will become clear, however, why the position of Navigator was regarded as almost a full-time job.

Is it hard to learn?

Frankly, yes. There are several reasons why:

If it is that much trouble, is it really worth it?

Absolutely! Celestial navigation is an interesting hobby in itself as well as a great starting point to the hobby of astronomy. Plus it gives us a sense of satisfaction and joy in keeping alive knowledge that connects us with nature and with our past, and actually does something useful, besides. Now there is a package deal!

By the way, is it expensive?

Outrageously so, especially compared to the prices of some of the "low-end" GPS (that is, Global Positioning System) receivers. So if you really want to learn and do celestial navigation, be prepared to spend a lot of money (anything from $250 to $2000 or more, as of 1996).

But if you just want to learn the general idea to satisfy your curiosity, you have come to the right Web Site!

Why are you doing this?

The Web has surprising little available about this topic. Although I don't claim to have seen every possible citation, I have seen mainly citations in on-line catalogs offering to sell books on the subject.

The absolute shortest explanation I have ever seen anywhere is written by Bill Myers. His one-page executive summary is excellent, but it provides no motivation for the ideas; hence, I offer the Web my relatively short, simple explanation.

How do you plan to explain it?

In the same manner as this Introductory page. I will pose questions that I have often been asked, in the hopes that they will "strike a nerve"; that is, they will be the very same questions and beliefs that you, the reader, have as well. As we go, the misconceptions should be removed and the concepts will be clear, if I am very lucky!

I strive for frequent divisions of the material into separate pages to try and keep loading times reasonable. If it all sounds appealing to you, then....

Go to the next Celestial Navigation page


Go to the Home Page of Al Placette

Go to the Home Page of Dr. Peck

Go to the Home Page of Purdue University