While a GPS is a pretty cool device that can tell you within a few feet what your position is, these devices won’t do you much good after the apocalypse. These devices require batteries or a charger to power them. And with no signals from ground control the satellites those GPS require to locate their position will start to drop out of orbit. So how do you navigate without a GPS, in the post apocalypse you’re going to have to go old school and that means using a compass for navigation. Pictured below is a typical orienteering compass and a list of it's parts. It's important to understand what each of these parts does to help aid you with your navigation.
Baseplate - can be used as a ruler to measure distance on a map
Scales - each compass has 2 different rulers for the two main scale measurements used on maps
Direction Of Travel Arrow - this is what you point in the direction you want to travel
Index Pointer - opposite end of direction of travel arrow and where you take degree readings
Dial - the ring around the housing that has degree markings engraved
Declination Marks - used to orientate the compass in an area with known declination
Orienting Lines - parallel lines marked on the floor of the housing and on the base plate
Needle - magnetized piece of metal that is painted red on one end to indicate North, unless the compass is damaged it will always point magnetic North
Housing - the main part of the compass, it is filled with liquid and contains the needle
Bubble - an air bubble is added to the housing to allow the user to know the compass is level
Mirror - lets the user see the compass face objects while navigating and can be used for emergency signalling
Sight - allows the user to aim the compass at distant objects
Basic Compass Reading
No matter the compass, one end of the needle always points north. Almost every compass made has the magnetic end of the needle colored red, but it’s always a good idea to check to ensure you know what end of the needle points to magnetic North.For example if you are north of the equator, sun around whichever end of the needle points towards the sun is south and the end that points at you is north.
If you're in a location such as Australia, the North end points towards the sun and the South end points at you.
To read your compass, hold it steadily in your hand so the baseplate is level and the direction of travel arrow is pointing straight away from you.
Keep it at about half the distance between your face and wrist so you can see the compass dial and the point your trying to navigate to.
Turn while keeping the compass in front of you.You'll see that as the compass rotates, the needle stays pointing the same direction (Magnetic North). Keep turning until the needle points in the direction you wish to travel.
(Tip) A common mistake many make is that if the needle is pointing east for example that you must be facing east. Remember to find your direction, you must turn the compass dial until the North mark and the "Orienting Arrow" is lined up with the North end of the needle. Then you can read the heading that is at the Index Pointer spot (the butt of the direction-of-travel arrow).
Since the Orienting Arrow is usually two parallel lines on the floor of the compass housing, a good thing to memorize is:
Take a Bearing
By moving your compass with your body and using the North, South, East, and West markings, you can get a pretty good idea which way you're going. This is often all you need, but, you'll probably notice on your compass, there are numbers and lines. These numbers and lines represent the 360 degrees in a circle that surrounds you no matter your position (Think of it like a clock and your in the center). When you need to find your way from one location, you need to use these numbers to find your bearing to that location. The direction you are going is called your heading. Heading and Bearing are pretty much the same thing. The image above is a heading of about 250 degrees.
Using your compass, take a few bearings. Move your body until the direction of travel arrow points at the following items and then turn the dial until the needle is in the arrow marker.Then read the bearing at the Index Pointer
Determining the bearing is like finding your heading, you turn to face the object, pick an object in the distance and one that stands out from the rest of the terrain. Remember this is the post apocalypse so you’re going to be tired and dehydrated so you want something as simple and obvious as possible to avoid confusion.
It’s important to keep a feel for general directions in your mind. If it's early morning and the sun is in your face, you are heading east with north on your left and south on your right. Remember, right and left are relative to your current heading. If you're in the northern hemisphere and the sun is at your back, you are heading in some northerly direction. In the southern hemisphere, the sun at your back means you are facing southerly.
This gives you a basic idea of how to use a compass, like all things this will take practice to master. Try taking some simple bearings on your next hiking or camping trip to get a feel for how it works. When travelling the wasteland remember to take several bearings as you travel to your destination as many of us have a heavy left or right foot which will lead us off course.