Northern Hemisphere
A surprisingly simple and easy way to use your watch as a compass only requires having enough sunlight to cast a shadow from a twig.
If you ever become lost, and do not have a compass, you can easily discover your direction by establishing a North-South line from your wrist watch. Here are the details…
In the Northern Hemishpere…
Align a twig (pointing up) at the edge of your watch so that it casts a shadow onto the face of the watch from the sun.
Then while holding the twig steady, rotate the watch until the twig’s shadow is cast directly onto the position of the hour hand.
In other words, you’re aligning the shadow with the hour hand (you’re pointing the hour hand in the direction of the sun).
Bisect the angle between the hour hand and 12-oclock. This halfway point between the hour hand and the 12-oclock position is your North-South line.
To determine which end of the line is north, remember this…
The sun rises in the east, and is in the east before noon.
The sun is due south at noon.
The sun sets in the west, and is in the west after noon.
Note: If your watch is set to daylight savings time, use the halfway point between the hour hand and 1 o’clock to determine the north-south line.
In the Southern Hemisphere
Align a twig (pointing up) at the edge of your watch so that it casts a shadow onto the face of the watch from the sun.
Then while holding the twig steady, rotate the watch until the twig’s shadow is cast directly onto the 12-oclock mark.
In other words, you’re aligning the shadow with the 12-oclock mark (you’re pointing the 12-oclock mark in the direction of the sun).
The halfway point between 12-oclock and the hour hand is your North-South line.
Southern Hemisphere
For the curious… the watch in the photo is a Luminox 1881.BO Blackout