Best Practices in

a Sun Compass to
Create a Magnetic-
Compass Deviation

How to purchase
a sextant

Sample Class Outline

Who We Are

BCOSA is an organization comprised of people who are interested in traditional navigation, in particular celestial navigation (also known as sextant navigation, star navigation, or if you are British, astro-navigation).

What We Do

We organize courses for people who want to learn to do celestial navigation — mostly by live video conferencing software. There are not many traditional navigators about in the world. The Internet helps the few of us there are to stay connected with each other, and to advance in our skills.

Why We Do It

The #1 reason, of course, is for fun.

When you think about it, the easiest and cheapest way to get nutritious, good tasting vegetables is to whip down to the local Safeway store, and pick some up.

But for all the supermarkets there are in the world, there are still some people who really enjoy growing a backyard garden. They take enormous satisfaction in eating their own tomatoes, and often will tell you that their tomatoes taste better than anything they can get in the store. They feel growing their own helps them get in touch with the earth, and may even help them center themselves spiritually.

It is much the same for celestial navigators. They don't use sextants because it is the only way, or even the best way, of getting a location fix. They do it because they enjoy navigating with "no batteries required". They take enormous satisfaction in getting a celestial fix. They feel it helps them get in touch not just with the earth, but with stars, planets, moon and sun.

That said, the bridge crews of Chevron oil tankers regularly practice celestial navigation because, as they say in this commercial from 2017, "at any time the GPS signal can be distorted or blocked."

There may also be something to be learned from the last voyage of the Varuna.

What Does a BCOSA Course Look Like?

Click here to see the outline of the course taught in the summer of 2019.

Maximum class size = 5 students.

How Much Does a Course Cost?

BCOSA offers a class comprised of 30 hours of live, fully-interactive, video-conferenced instruction for $500 CDN, which includes textbook and reference materials (e.g.Nautical Almanac) shipped anywhere in the world.

If you would like to explore other opportunities for learning celestial, do consider these.

Are There Any Other Expenses?


Classes will be fully interactive, so if your computer does not already have a webcam and microphone, you will need to purchase those items for yourself.

You will need basic navigational plotting tools, such as drafting compass, protractor, and parallel rule. If you do not already own these, your instructor will make some recommendations from Amazon.

There is always a bit of a mental hurdle for learners as they try to visualize the 3-dimensional earth using drawings on 2-dimensional paper or computer screen. So while not essential, if you have a 12" globe of the earth, you will find it helpful to you as you try and visualize Great Circle routes, and the navigational triangle.

If you don't already have one, you may want to purchase a sextant. Click here for a discussion about that.

More Information