Analog Watch as a Compass

Have you ever wondered how you’d get home if you were lost without GPS technology to guide you? Some people have magnetic compasses that can tell them where the cardinal directions are, but other do not. Most people, however, do have an analog watch. Even cell phones often have an analog clock widget that can be used. Here, I’m going to show you have to turn an analog watch into a compass. If you only have a digital watch, you can still draw the analog clock and this method will still work.

Ok, so first let’s go over the principles. No matter where you’re at in the world, no matter what day of the year, the sun always rises in the east and sets in the west. This is because the Earth rotates west to east as it revolves around the sun. Depending on the season, the sun may rise a little bit toward the south or north direction. This has to do with the axial tilt of the Earth and its position relative to the sun along the orbit of revolution.

The four astronomical seasons viewed from the North. Do see how the position of the Earth and its axial tilt affects where the sun rises? During the equinoxes, the sun rises true east to true west. During the solstices, the sun will either a bit toward the north or a bit toward the south.

 

This shows how the sun appears to rise along the horizon for the different seasons.

The fact that the sun rises on the east, or approximately east, is a key fact that can be used to navigate. If you know where east is, then you should be able to deduce the other cardinal directions. However, the sun isn’t static and won’t stay in sunrise position all day. So, we need to account for the hour of day in relation to the sun’s position. We also need to know which hemisphere on Earth we’re on. Fortunately, many of us know which hemisphere we’re on or will be if we’re traveling. This method won’t work well near the equator. If you’re in the northern hemisphere, when you face the sunrise, the equator (to the south) will be at about a 90 degree angle to the right of the sun. If you’re in the southern hemisphere, when you face the sunrise, the equator (to the north) will be at about a 90 degree angle to the left of the sun.

Northern Hemisphere

Alright, so with your analog watch set accurately to true local time, hold your watch parallel to the ground and point the hour hand toward the sun.

Exactly, just like this except the watch should be parallel to the ground. If you’re having trouble aligning the hour hand to the sun, put a stick in the ground and align to the narrow part of the shadow.

Now, bisect the angle between the hour hand and the 12 o’ clock mark. Before noon, you should bisect counter-clockwise from the 12 o’ clock mark. After noon, you should bisect clockwise from the 12 o’ clock mark. So, if it’s 3 in the afternoon, then your bisected line would be at 1½.

Lines showing the direction of the sun (yellow), the 12 o’ clock line (green), and the bisected angle (red). The angles look wrong in the picture because of perspective.

This bisected line points south. Now, you can deduce the other cardinal directions no matter what time of day! But what about the southern hemisphere or daylight savings time?

Southern Hemisphere

The method described above works just the same in the southern hemisphere with a couple minor differences. First, point the 12 o’ clock mark toward the sun, not the hour hand. Then bisect between those two just the same as in the northern hemisphere. Counter-clockwise before noon, clockwise afternoon. Also, the bisected angle points north instead of south this time.

Daylight Savings Time

Some countries or people practice what is known as daylight savings time. This is the practice of advancing clocks one hour during summer so that the light extends during the evening hours. This method only works exactly as described if your watch is set to true local time. So, if you have your watch set to DST, just substitute the 12 o’ clock mark with the 1 o’ clock mark.

But I don’t have an analog watch…

What? Why not? They’re quite stylish! Oh well, this just means that you’ll have to note the time with your digital watch and draw an analog clock relative to the sun. You don’t need pen and paper, just get a stick and draw in the dirt.