Having a compass with you while hiking is already a great start. Knowing how to use it and navigate with it is even better! The compass is a simple tool that works at all times and, combined with a map, will help you get out of most navigation situations. Here are some basic tips for using a compass effectively while hiking or on a trek — complementing the other navigation advice already shared on this site.
Compass description
A compass has at least 3 components:
- A moving magnetised needle, whose red tip indicates Magnetic North.
- A direction arrow: a fixed arrow on the compass baseplate that you point towards the direction to follow or towards a landmark; the direction arrow can also be the edge of the compass baseplate.
- A graduated rotating dial.
It should be noted that the needle indicates Magnetic North. There is a difference between Magnetic North and Geographic North: this is called magnetic declination (magnetic declination is shown on IGN maps). At our latitudes, it is relatively small and can be disregarded over a typical walking distance. In regions closer to the poles, it is essential to correct your bearing for magnetic declination and to equip yourself with a specific compass.
Compasses can also be fitted with a mirror sighting dial, which makes them easier to use and allows for more precise sighting.
A compass is sensitive to magnetic fields: do not use it too close to a phone battery, and certainly not under power lines!
The compass will allow you a few basic uses: locating yourself on a map and following a direction to reach a destination.
Using a compass to orient your map
Orienting your map is essential before making any other use of the compass and before reading the map. Every time you take stock of your position, this is the first step to carry out. Of course, you can orient your map using a few landmarks or your sense of direction, but compass orientation will be more precise and free from errors of judgement.
Place the compass on the map and position it so that the direction arrow points to the map's north and is parallel to the north–south axis of the topographic map. Depending on the map brand, north is indicated in different ways, but it is generally the top of the map or the grid lines.
Once the compass is correctly positioned, rotate the entire "map + compass" assembly in the horizontal plane until the magnetic needle aligns with the direction arrow. At that point, your map is correctly oriented to North. Every direction on the map corresponds to a real-world direction on the ground.
Using a compass to locate yourself on the map
Imagine you are on a path marked on the map but you don't know exactly where you are on that path.
First, orient your map to North as described above. Then identify a prominent landmark in the landscape that you can clearly locate on the map: a church steeple, a distinctive summit, a radio transmitter mast, a peak, a water tower… and so on.
Without rotating the map, but simply moving the compass, point the direction arrow or the right edge of the baseplate towards the characteristic point shown on the map while sighting it in the field. The line of direction thus established intersects your path at the point where you are located.
It is possible to repeat the process for greater precision, or to carry out a triangulation (sighting three landmark points) to determine the area you're in with reasonable accuracy.
Using a compass to follow a bearing
Imagine the following situation: you know where you are (point A) and you want to reach a hamlet you can see in the distance (point B), but you know that due to the folds in the terrain you're going to lose sight of it.
- First, point the compass's direction arrow towards your objective — point B on the map or in reality: the compass is then aligned along the straight line connecting point A to point B.
- Rotate the rotating dial until the North on the dial coincides with the North indicated by the moving needle.
- Then read the azimuth (bearing to follow): this is the value displayed in the direction of the magnetic needle
Keeping your compass horizontal with the magnetic needle's north always aligned with the north on the dial, you can walk in the right direction by following the indicated bearing. Make corrections whenever point B, your destination, comes back into view, and adjust your direction if you need to navigate around an obstacle or make a lateral move.
Using a compass takes a little practice, but it's not complicated. Don't hesitate to practise in familiar terrain or to run small navigation exercises on a hiking route you know well. This will give you confidence for the moments when you find yourself in unknown territory and need to use a compass. Having a compass with you while hiking and on a trek is essential — and so is knowing how to use it well! You now know the basic rules, and we'll be back soon with a new article to share more advanced concepts.
