Navigating by day without a compass


Using Shadows During The Day

Introduction

The earth's relationship to the sun can help you to determine direction on earth. The sun always rises in the east and sets in the west, but not exactly due east or due west. There is also some seasonal variation. In the northern hemisphere, the sun will be due south when at its highest point in the sky, or when an object casts no appreciable shadow. In the southern hemisphere, this same noonday sun will mark due north. In the northern hemisphere, shadows will move clockwise. Shadows will move counterclockwise in the southern hemisphere. With practice, you can use shadows to determine both direction and time of day. The shadow methods used for direction finding are the shadow-tip and analog watch methods.

Shadow-Tip

  1. Place the stick or branch into the ground at a level spot where it will cast a distinctive shadow. Mark the shadow's tip with a stone, twig, or other means. This first shadow mark is always west--everywhere on earth.
  2. Wait 10 to 15 minutes until the shadow tip moves a few centimeters. Mark the shadow tip's new position in the same way as the first.
  3. Draw a straight line through the two marks to obtain an approximate east-west line.
  4. Stand with the first mark (west) to your left and the second mark to your right--you are now facing north. This fact is true everywhere on earth.

Stick-Tip Method

Inclining the stick to obtain a more convenient shadow, in size or direction, does not impair the accuracy of the shadow-tip method. Thus, a scout on sloping ground or in a highly vegetated terrain need not waste valuable time looking for a sizable level area. A flat dirt spot the size of your hand is all that is necessary for shadow-tip markings, and the base of the stick can either be above, below, or to one side of it. Also, any stationary object (the end of a tree limb, or the notch where the branches join) serves just as well as an implanted stick, because only the shadow tip is marked.

Telling Time with Stick-Tip Method

After completing the Stick tip method. The resulting graph can give you some fairly accurate time method. What I've produced is a view from the top after using the method above to find direction. The illustration below is based on the 24 hour clock or "Military time".

  1. Starting from the stick, if you draw a line that splits the difference between the first tip and second tip, you'll accuratly show 1200 hours (12 noon).
  2. Due east from the stick will be 1800 hours (6:00 pm)
  3. Due west from the stick will be 0600 hours (6:00 am)
  4. The current shadow from the stick will be the current time.

Telling Time with the Stick Tip Method

Determining directions and time by shadow

Determining directions and time by shadow

Analog Watch Method

A watch can be used to determine the approximate true north and true south. In the north temperate zone (northern hemisphere) only, the hour hand is pointed toward the sun. A south line can be found midway between the hour hand and 12:00 Noon, standard time. If on daylight saving time, the north-south line is found between the hour hand and 1:00 pm. If there is any doubt as to which end of the line is north, remember that the sun is in the east before noon and in the west after noon.

For Troop 780 we are in the Northern Temperate Zone

What I do is;

- Leaving your watch on your wrist, take a small straight stick about 1/8 to 1/16 inches (Yes real thin)
- Place the bottom of the stick on your wrist touching the outside rim of your watch so that it forms a 90° angle with the hour hand.
- Rotate your body so the stick is facing the sun and stop when the sticks shadow aligns perfectly with the hour hand on your watch.
- This is a much more accurate method than simply aiming the hour hand at the sun.

Analog Watch Explanation

The watch may also be used to determine direction in the south temperate zone (southern hemisphere); however, the method is different. The 12:00-Noon hour dial is pointed toward the sun, and halfway between 12:00 noon and the hour hand will be a north line. If on daylight saving time, the north line lies midway between the hour hand and 1:00 pm.

The watch method can be in error, especially in the lower latitudes, and may cause you to circle. To avoid this, make a shadow clock and set your watch to the time indicated. After traveling for an hour, take another shadow-clock reading. Reset your watch if necessary.


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