An indispensable device for getting your bearings, a compass is one of the first things you should pack when going on a hike. Extremely useful for orientation, it is one of the best ways to get you from point A to point B. Still, you have to know how to use it to make sure you’re on the right track!
Parts of a compass
- Direction of travel arrow (on the compass base plate): Points towards your destination or a landmark.
- Magnetic compass needle (moves freely): Red indicates north.
- Rotating bezel/degree dial: Allows you to find your bearings by calculating the angle (on the horizontal plane) between the direction of an object and a reference direction (called the azimuth).
- Orienting arrow (in the window of the dial): Used for orientation without a map.
- Map scale/rulers: Allows you to calculate the distance to your destination.
The difference between true north and magnetic north
True north refers to the north pole at the top of the axis that the earth rotates on: the northern point where all meridians (lines of longitude) converge on a map. Magnetic north, on the other hand, refers to the place on the earth’s surface where its magnetic field goes vertically down into the planet. Compasses point towards magnetic north, which does not exactly correspond to true north, and actually changes geographic position all the time.
How to use a compass with a map?
- Unfold your map.
- Place your compass on your map, on a line that connects your point A to your point B.
- Make sure that the compass is flat, otherwise the needle might not be able to move freely to point towards the north.
- Point your direction of travel arrow towards your destination.
- Rotate the compass dial until the needle points to north on the dial (north is always at the top of a map).
- Follow the direction indicated by the direction of travel arrow, making sure the red needle is always pointing north on the dial.
What is an azimuth?
It's the angle that is formed between north (on your map) and your direction of travel and has a value of 0 to 360 degrees. Your azimuth is the number that the direction of travel arrow indicates on the dial.
How to use a compass without a map?
You are at point A and want to get to point B:
- If possible, find an open space.
- Look for landmarks like mountain peaks, a village, buildings, or a river.
- Point the direction of travel arrow at one of the landmarks, then rotate the dial until the orienting arrow lines up with the red needle.
- Follow the direction of travel indicated by the base plate of the compass while making sure that the red needle always points north on the dial, in line with the orienting arrow/window.
