When is the best time to use the sun for navigation?

Maximizing Accuracy

When using the sun for navigation, it’s essential to understand that the sun’s position changes throughout the year due to its elliptical orbit around the Earth. At the equinoxes (March 20/21 and September 22/23), the sun rises due east and sets due west, making it an ideal time for navigation. However, at the solstices (June 20/21 and December 21/22), the sun’s path is more northerly or southerly, affecting its position in the sky.

Using Shadows

One technique for navigating with the sun is to cast a shadow stick. At the equinoxes, the shadow stick will point due north or south, depending on the hemisphere. In the northern hemisphere, the shadow will point north, while in the southern hemisphere, it will point south. By using a stick or a pencil, you can create a makeshift sundial to estimate the time and direction.

Understanding Declination

To accurately navigate with the sun, you need to consider its declination, which is the angle between the sun’s position and the celestial equator. By using a declination chart or an ephemeris, you can determine the sun’s declination for a specific date and location. This information, combined with the sun’s altitude, can help you determine your latitude and direction.