An ability to navigate by the sun makes you a better navigator and increases your competence in the great outdoors.
You're following a westerly compass course through dense, swampy woods late in the morning on a sunny day. Your catching feature is the more or less north-south road where you left your Jeep. A blister develops on your foot, and you stop to treat it before it gets worse. After taking care of your foot, you enjoy a snack and some water. Some time later, you once again head out for the road. After walking a short way, you reach into your pocket for your compass. It's NOT there! Maybe you set it down when you stopped a while back. You backtrack but can't find it. In the slight panic, you've gotten turned around, and aren't sure which way is back to the road.
Now what? How will you find your Jeep?
The Sun Provides Back-up Navigational Information
Even with a compass, a good navigator will take notice of the sun when it's available, since a good navigator never likes to rely on any one piece of information. The sun's position reassures that the compass is accurate--or inaccurate, as the case may be.
Having determined your intended direction with a compass or maybe a GPS, notice where the sun is while heading in that direction. Then, instead of following either instrument, you may find it easier to use the sun as a temporary directional guide. Since the sun moves across the sky at 15 degrees per hour (360 degrees in a circle / 24 hours in a day), you can use the sun's guidance with reasonable accuracy for at least 20 minutes.
Or instead of using the sun, use shadows to guide you. In Scenario 2, to keep the south-bearing sun off your left shoulder, make sure your shadow falls to your right, and guide off your shadow instead of off the sun. In this situation, the shadows of trees and other objects should lie across your path. If they begin to lie parallel to your path, you'll know you're going in the wrong direction.
Accurately Navigating by the Sun
After learning to navigate by the sun (to do this, be sure to see the other sun-related links on the Celestial Navigation page), and after some practice, you should usually be able to find directions by the sun to within about 10 degrees. If you make good use of pathfinding skills, such accuracy should be sufficient to find your way across the terrain.