Compass 101

Knowing how to use a compass and read a map is a very useful skill and especially important when hiking in areas unknown to you or your companions. Keep yourself on track when hiking by levelling up your compass reading ability.

“In 300m, turn left”, most of us now rely on our smartphones to give us directions. However we’ve all had at least one experience of being told an obscure way to go or finding ourselves lost regardless. 

And what happens if you don’t have reception or your phone battery dies? Knowing how to use a compass and read a map is a very useful skill and especially important when hiking in areas unknown to you or your companions. Keep yourself on track when hiking trails or navigating dirt roads by levelling up your compass reading ability.

First you’ll need a physical map: whether it’s an impossibly large, folded-7-different-ways piece of paper, a simple print-out from an information centre or a ancient treasure map, you need to have landmarks such as particular sites, streets, intersecting paths or elevation points to find your bearings. Bonus features include elevation indicators, scale bar, contours, legend, symbols and declination angle.

And you'll need a compass:  The main compass features are outlined below:

Compass parts

• Base plate: the clear rectangular body of the compass with rulers down the straight edges, useful for measuring distances.
• Direction-of-travel arrow: if you’re thinking this is self-explanatory, you’re right! Once you’ve got your bearing, this will be the direction you need to travel.
• Magnifying lens: useful for magnifying sections of a map, especially if the print is fine or a symbol is small.
• Orienting arrow: helps to orient the bezel
• Orienting lines: inside the compass housing, these lines help align the compass with true north when used in conjunction with a map.
• Rotating bezel: a ring around the compass housing that has degree markings from 0 to 360 (or 0 to 6400 for a military compass).
• Declination scale: degrees of difference between true and magnetic north. More on this shortly.
• Magnetised needle: the floating needle that always points to magnetic north. Usually, the north end is marked in red. 

Where is North? 

• North is north, right? Not quite, as there are two terms: “true north” (AKA geographical north) and “magnetic north”. True north is a fixed point that we consider to be the north pole (or the location of Santa’s workshop). Magnetic north is where your compass needle points, and can vary over time and depending on your location. The difference between magnetic and true north is called the ‘declination’. For example, in Western Australia, magnetic north is 5º west of true north, but on the east coast, magnetic north is 15º east of true north.
• Walking a few blocks in a general northerly direction in a town without accounting for declination won’t make much of a difference, but relying on a compass in the vastness of the bush can cause you to go off-track if you don’t correct for the declination. If you’re going to try orienteering, or take long (or multi-day) hikes, knowing how to find true north can save you a lot of time and keep you from getting lost. 
• When preparing to hike, check the declination angle of the location where you are hiking (this may be on the local parks website or printed on your map). Rotate the bezel according to the degree and direction indicated. When the needle lines up with the orienting arrow, the North marker on the bezel will indicate true north and can then be used confidently.
• *Note: maps drawn for orienteering may have magnetic north/south lines on the map rather than true north, which avoids needing to correct for declination.

Globe Image from GISGeography

Find your location on a map

First you’ll need to know where you are. To find your location, you’ll need to be able to spot at least one landmark, two or more is better: mountain, river, information point, path bend, etc. and cross-reference that with your map.

Find the route to your destination

• Make sure there are no metal objects nearby that could interfere with your compass.
• Identify your current location and destination on a map, and place the compass on the map so the edges of the base plate connect your current location with your destination.
• Keeping the base plate steady, rotate the bezel until the orienting lines in the compass housing align with the north-south lines on the map.
• Then account for declination, by rotating the bezel east or west by the number of degrees specified.
• Hold the compass level in front of you and rotate your body until the red end of the compass needle lines up with the orienting arrow inside the compass housing. Remember “red in the shed”. As you rotate your body, keep the compass in front of you. Move your feet, not your hands!
• The direction-of-travel arrow now points in the direction you need to go.

Tips to get the best from your bearings

• Practice in a familiar area before relying on a compass in unknown terrain. 
• Regularly check your bearing to stay on course.
• Remember that a compass does not tell you the distance to your destination, only the direction. Use the map’s scale and the scale ruler on your compass if you need to calculate the distance too.
• Make sure you know where you are as you take the bearing, so the back edge of your compass stays aligned.

Types of compass

So far, we’ve talked about plate compasses, which are great for beginners and surviving in the bush, but there are plenty of other compasses, and variations of the plate compass:

• Thumb/Wrist compass: these compasses are designed to be strapped to your hand for frequent bearing-checking. These compact compasses are especially valuable for orienteering.
• Elite/fast-setting: As you use your compass, you’ll start to notice that the needle can wiggle around a bit before finally settling on north. While it doesn’t matter to most, any kind of race requires a super fast-setting needle to take bearings quickly.
• Degrees/military mils: These are just two different ways of breaking up the circle to communicate bearings to other people. For most civilian uses, degrees are best, though the military uses mils. Some race compasses dispense with both measurements, and replace them with a colour-scale for quick reference, or a totally blank bezel.

Using a compass effectively takes practice, especially when it comes to understanding how it interacts with a map. Once you’ve got the skills down pat, you can really focus on nature and enjoy the thrill of using a new skill. If you’ve got the compass bug, then consider signing up to your local orienteering club or taking part in an adventure race.