Staying found is a useful skill if you are going to spend a lot of time exploring your natural environment. Learning how to use a map, compass, and GPS devices can help ensure that if you get lost, you can find your way back.
Orienteering is the skill of finding one's way through unfamiliar terrain with the aid of a map and compass. Typically, orienteering is done in the wilderness but the basics can be practiced anywhere. Some people compete in orienteering competitions, in which they are timed as they complete a pre-determined course. The winner is the participant who completes the course in the fastest time.
As an orienteer, you must make decisions and calculations: reading maps, recognizing terrain, choosing routes, and setting the compass. These mental challenges can make orienteering fun and exciting.
The basics of orienteering can be learned in less than an hour, but you can spend years perfecting your skills.
You can get started with just a map and compass. There are many types of compasses ranging from tiny thumb compasses, often used in orienteering competitions, to complex high-tech compasses, like the ones used by the military. For most hikers, a basic orienteering compass works just fine.
How to use a compass
The first things you need to learn about using a compass are the directions: north, south, east and west. For our purposes, north is the most important. But - and this might confuse things a bit - there are three types of north that you need to learn:
- Grid North: the direction of the grid lines on a map.
- True North: the point in the northern hemisphere marking the axis around which the earth spins. (Don't let the name fool you. True north isn't necessarily the most important or accurate north; it is just its name).
- Magnetic North: the direction indicated by a magnetic compass. (Magnetic north moves slowly over time.)
Finding Magnetic North
One thing to remember is that a compass finds magnetic north - not true north or grid north (except by coincidence in some areas). When you read north on a compass, you're actually reading the direction of magnetic north.
A basic orienteering compass has a floating needle in the middle of the compass housing. (The compass housing is the turnable part on the face of the compass). The needle is usually painted red and black. When you hold out your compass, the red part of the needle points to magnetic north. And that's all there is to it. You've just found magnetic north.
Note: If you are carrying something of iron, it might disturb the arrow. Even a staple in your map might be a problem. Make sure there is nothing of the sort around.
But what about west, east and south?
To find the other directions, line up the N on the compass housing with the needle's red point. Once the N and the needle are lined up, use the W, E and S on the compass housing to determine the other directions - W for west, E for east and S for south. An easy way to remember the directions is to say to yourself (N)ever (E)at (S)hredded (W)heat - starting from north, east, south and west follow in a clockwise direction.
Using a map and compass to find your way
If you're looking to get somewhere using a map and compass, the first thing you need to do is figure out where you are starting from on your map. Fortunately, maps have features that can help you determine your location. These features include roads, trails, streams, and rivers. If you don't know where you are, but you remember seeing a feature that can help identify your location, go back to that reference spot and start from there.
You can also use map contours to help identify hills, ridges and valleys. Contours are lines on the map that indicate how much higher or lower you are than sea level. On maps in the Bruce Trail Reference, each map shows heights of land by contour lines in multiples of 10 metres. The closer together the contours, the steeper the slope. Ring contours indicate hilltops. Valley contours tend to pint in a v-pattern upstream. A similar pattern can indicate a ridge or spur, but in most cases the inside contours will be of a higher altitude than the outer contours.
Once you know where you are on your map, get out your compass and follow these steps to get where you want to go:
- Draw an imaginary line on your map from where you are to where you want to go, and then place your compass edge along that line.
- Rotate the compass housing so that the lines on the compass housing match with the gridlines going north and south on the map.
- Then, adjust the compass dial accordingly to make up for the declination degree noted on the map. (We'll get into this below. Setting your declination can be the hardest part of finding your way using a compass).
- Now hold the compass out in front of you and rotate your body until you get the needle match (when the red needle matches the red north arrow on the dial).
- Once needle match has been accomplished stretch your arm out in front of you with compass in hand. If you have a mirror you should angle it so that you can see the compass housing and the direction that you wish to walk in at the same time. Choose a landmark such as a tree in the near distance. Having needle match, walk straight ahead to your chosen landmark. Again, gain needle match, choose another landmark and continue.
Introducing, from the land of confusing concepts, declination!
What is declination? Declination is the angular difference between magnetic north and true north. Declination can also be referred to as magnetic declination.
What does that mean? Well, maybe the best way to describe declination is in a picture. However, since we will be referring to the Bruce Trail Reference, the angular difference of most interest to us is between magnetic north and grid north. This angular difference is known as grid declination.
Why do I need to know about declination?
If you fail to adjust your compass for declination, any readings you get from your compass could be wrong and you may wind up far from where you want to be (or in other words, lost L). This is because your compass finds magnetic north, but the lines on your map are drawn using grid north. Setting declination will match your compass reading (magnetic north) with the grid lines on the map (grid north), allowing you to accurately find your way.
The picture shows you standing 10km from your house and indicates the direction of grid north and magnetic north. For the sake of this example, you and your house line up perfectly along grid north and you and your neighbour's house lines up perfectly with magnetic north (keep in mind that this is a made up example and that the distance between magnetic north and grid north wouldn't usually be this great over a distance of just 10km).
So, from where you are standing in the picture, if you were to use your compass to find magnetic north, and then follow the compass' arrow for 10km, you'd end up at your neighbour's house. Which is fine, if that's where you wanted to go.
But what you were asked you to follow your compass to your house? How would you do that? You can't follow the grid north lines, because they aren't drawn out on the planet for us to follow. We need to find a way to get our compass, which finds magnetic north, to line up with grid north. And there is a way to do this using declination.
Like most maps, the Bruce Trail Reference's maps contain a diagram in the margin which gives the declination for the year in which the map was published. A lot of maps will show the difference (declination) between magnetic north (indicated by MN) true north (indicated by the "star"), and grid north (indicated by GN). Because the Bruce Trail Reference is drawn according to grid north, the diagram only shows the difference between magnetic north and grid north.
After finding the declination on the map, you need to transfer that information to your compass. Some compasses set declination by turning a screw on the side of the compass until the reading on the circle in the compass lines up with the proper declination. For many other types of compasses you can set the declination by simply rotating the compass housing until it lines up with the indicator marker at the proper declination. If neither of these methods work with your compass, check your user's guide, as it should have instructions on setting the declination.
Should I bother setting declination? Isn't getting to my neighbour's house sufficient?
Sure, if you're looking for something big over a short distance, you probably don't need to worry about setting declination. You'll get close enough to what you're trying to find. But if you're looking for something small or trying to get somewhere a great distance away, you'll want to be more accurate and will need to adjust for declination.
Keep this in mind: depending on where you're on the earth, the angle of declination will be different - from some locations, declination is minimal, but from other spots, the angle between the norths can be pretty big. There are few places where true north and magnetic north are perfectly aligned and these are called agonic lines. In North America, one runs through Florida up to the Great Lakes and into the Arctic Ocean. The declination for each map in the Bruce Trail Reference is between 9 degrees W and 12 degrees W.
Global Positioning System (GPS)
An alternative to using a map and compass to find your way is using a GPS device. GPS stands for Global Positioning System and is a global navigation system that uses satellites to identify where you are on the planet. GPS can be used freely by anyone (as long as you have a device that can read the satellites' signals) and is often used for navigation purposes.
GPS is a useful tool for map-making, land surveying, commerce, scientific uses, tracking and surveillance, and hobbies such as geocaching.
Geocaching is treasure-hunting game in which participants use their GPS to hide and find "caches" somewhere in the world. Typically, the treasures are left in a small waterproof container containing a logbook and a treasure. The treasures are usually of little value.
If you are going to participate in geocaching along the Bruce Trail, remember to keep to areas that are close to the trail, as much of the land the Bruce Trail runs along is environmentally sensitive and can be damaged by pedestrian traffic.