A compass is one of the essential pieces of gear you can bring on a hike. A map is virtually useless without a compass to indicate where north is. While a GPS for hiking may have its uses, it’s not smart to rely only on that alone. The battery can go dead and without a map and compass skills, you can be left stranded. How to read a compass, along with knowing how to read a topographic map, is among the most crucial survival skills.
THE BASIC PARTS OF A COMPASS
There are many different types of compasses on the market nowadays, but they all have the same purpose. That is, of course, allowing you to find north and navigate your way in the wilderness. Although all compasses point north, many of them come with extra features and components.
1. MAGNETIZED NEEDLE
The typically red-coloured part of the magnetised needle always points to the magnetic north pole. Not true north, more on that in a moment.
2. ROTATING BEZEL
The rotating bezel has markings on its outer edge, called azimuth ring. These markings range from 0° to 360° and include the four directions (north, east, south and west). This bezel rotates around the compass needle.
The baseplate is a transparent plate with several different markings and lines. They include the direction-of-travel arrow and a ruler to measure distances on a map.
4. ORIENTING LINES AND ARROW
Orienting lines are the markings inside and underneath the compass housing. They rotate with the rotating bezel while the magnetised needle keeps pointing north. The orienting arrow lies in the middle of the orienting lines and the rotating bezel. It aims to the north on the rotating bezel’s azimuth ring.
HOW TO READ A COMPASS
Reading a compass is pretty straightforward. It’s the first step in using this valuable outdoor tool. You only need to know one thing if you want to read a compass – one end of the needle always points north. The north-pointing end is almost always red while the other part of the needle may be white, black or another colour.
Here are a few tips on how to read a compass correctly,
1. When holding the compass, make sure that the baseplate is level and the direction-of-travel arrow points away from you.
2. Hold it at a height between your waist and your face, and close to your stomach. Your elbow should be slightly bent, and your arm relaxed.
3. Look down and see which direction the needle points.
HOW TO USE A COMPASS: 4 STEPS TO FOLLOW
You can use a compass for various reasons and in many ways. Its applications range from finding north to navigating the unmarked wilderness and finding your position.
Below, we’ll outline how to use a compass in its most used way, finding north and setting a direction.
1. FIND NORTH
The only thing a compass does by itself is point north. You’ll have to do the rest. As pointed out above, the red end of the needle always points to the magnetic north. The first and most natural step.
2. ORIENT YOUR MAP
The top of a topographic map always points north as well. Now, it’s a matter of lining up your compass with your map. You do that by first aligning the orientating arrow on the rotating bezel with the direction-of-travel arrow on the baseplate.
Next, put your compass on your map so that the orienting lines and arrow parallel the vertical, or north-south, lines on the topographic map. Keeping your compass in place on the map, turn your map until the magnetic needle overlays the orienting arrow. Now, your map points north.
3a. SET A DIRECTION (WITHOUT A MAP)
If you don’t have a map, you’ll have to rely on a visible landmark to set a direction. You can also set a route without a map if you know which direction (north, east, south, west or any direction in between) you want to go in.
Point the direction-of-travel arrow toward the landmark you want. Now, turn the rotating bezel so that the orienting arrow overlaps with the magnetic needle, pointing north. Making sure the needle always aligns with the orienting arrow, all you need to do is follow the direction-of-travel arrow.
Setting a direction when you only know a direction works pretty much the same way. Instead of pointing the direction-of-travel arrow at your goal landmark, though, you will have to line up your preferred direction with the direction-of-travel arrow.
Say you would like to go east. What you need to do is turn the rotating bezel until it the letter “E” or word “East” on the azimuth ring aligns with the direction-of-travel arrow on the baseplate. Then, turn the compass so that the magnetic needle overlaps with the orienting arrow.
Just like above, keeping the needle aligned with the orienting arrow at all times and merely following the direction-of-travel arrow will take you to where you want to go.
3b. SET A DIRECTION (WITH A MAP)
The beauty of a compass only really shines when used together with a topographic map. Setting a direction using a map follows the same principles as the techniques above. What makes it so much better is that you can set routes to destinations or objects that aren’t visible.
The only thing you need to know is where you are on the map. If you don’t know where you are, you can use a map, compass and two visible landmarks to triangulate your position.
Now, find your destination on the map and visualise or even draw a direct line between your position and your objective. Line up the edge of your compass’ baseplate with that line, making sure that the direction-of-travel arrow points toward your goal.
Next, rotate the rotating bezel until its orienting lines parallel the lines on your topographic map. Then, hold the compass in front of you, as explained earlier, until its magnetic needle aligns with the orienting arrow.
You will now face the direction of your objective. If you keep the needle and the orienting arrow aligned, you can follow the direction-of-travel arrow to get to where you need to be.
4. TRUE NORTH VERSUS MAGNETIC NORTH
A compass needle always points to the magnetic north pole, which is not the same as true north. Topographic maps happen to be oriented toward true north, so that’s something that needs to be taken into account.
The difference in angle between magnetic north and true north is called declination. Depending on where you are in the world, this difference can be rather significant. We’re talking 15° or 20° or even more.
Every topographic map has a declination diagram, generally found in its lower right corner.
When using your compass and topographic map, make sure to account for this difference. You can do this by using the degrees on the edge of the rotating bezel, the azimuth ring. Mark the declination degree with a marker or a piece of tape, or write it down, so you don’t forget.
When setting a direction and aligning the compass needle with the orienting arrow, this is when you need to account for this declination difference. As you navigate your way, always ensure that the needle points at the true north and not at the magnetic north.