How to use a Compass
Before there was the compass, all navigation was dependant on the sun during the day and the stars at night. Whenever it was cloudy or foggy, you were lost!
Today we have state of the art technology to tell us where we are anyplace on earth within a few feet of accuracy.
These devices can also be used in the wild, but today lets start with the compass and gather all of the basics before we blast off into orbit.
The compass was originally invented by the Chinese somewhere around the 11th century AD. They discovered that by suspending a sliver of "Lodestone" on a string.
Lodestone is a mineral found in nature. It is the most naturally magnetic mineral known so it would always point in the same direction.
By the next century they were navigating using compasses not a whole lot different than today, in principal.
What we are going to do here is learn how to use that old dependable compass, your best friend out in the wilderness. It is also called "orienteering".
Orienteering is using both a map and a compass together to either find your way or locate your self in relation to physical features that are in sight.
With just a relatively competent understanding of the compass and how to orient it to a map, you will very quickly learn to navigate around the great outdoors. It is not all that difficult, so let's get going.
What Makes a Compass Work?
Our planet Earth is blessed with a magnetic field between the North and South Poles. A compass is simply a device that uses that field for finding directions. That allows a magnetized needle, or pointer, to align itself in those magnetic lines of force.
Finding North
Finding which way is North is the simplest thing to do. Just set the compass down on the table or any flat surface and... North appears.
The needle quickly spins around and lines up in those lines of force and points North and South. The colored end (usually red) is north.
Please do NOT use the compass next to anything made of iron, electronic or anything else that is magnetized. The needle itself is a magnet and your directions will be off by quite a bit!
Cardinal Points
This is what we call the four major directions, North, South, East and West. These are clearly marked on the face of the compass.
There are far more than these four. Halfway between each of the four main points are four more. Starting at North and going clock-wise these would be North East, South East, South West and North West. We have all heard these terms before, I am sure.
There are a total sixteen that are commonly used, These would be between the last named points and would be North-North East, East North East and on around.
See if you can name them all. It's not hard. See the Compass Rose at the bottom of the page and you will see all sixteen points. Get to know them.
It's a Matter of Degree
The compass is divided up into small increment called Degrees. There are 360 of them that form the entire circle around the compass. This is the major defining system you will be using in conjunction with a map to locate something, or yourselves. But first, let's find out how to use the compass!!
First lets ask why 360 and not something else like 400? It goes far back into history when the Mesopotamians used the number 60 as a basis for their entire numbering system.
Later the Egyptians picked up on that same system and were the first to denote a full circle to have 360 degrees. So... the system was well in use several thousand years before the compass was even invented.
Referring back to the compass, that makes each major cardinal point N, E, S &W exactly 90 degrees apart and the other points even less. From North to North East is 45 degrees, half the distance to East, and so on.
Now Let's Go Use It!
Go outside for this part and bring a map with you, any plain old street map will do.
A compass has little value inside a house so let's put it to use where it is supposed to be helpful for us. Either set it down on a flat surface or if you are steady enough try to hold it in your hand.
The important thing is that the needle is free to turn and not binding on the body of its case. That will produce a false reading.
See the needle pointing to the North.
At night, if you can find the North Star, see how it lines up.
Now find an object, say a tree, a rock, a building or anything that a distance away. Move your body facing the object and look at the compass.
Find the "Degrees" that the object is from North. That is its direction, bearing or its azimuth. All three terms mean the same. This could be the direction you need to go in the wilderness and stay on a straight line, know which trail to take or the bearing of a feature used to locate yourself.
Do this to different objects in at least three different directions so you can see the use of the Degree numbers. This will help you become familiar with it.
Have someone verify what you are doing and the direction. In the field it is always good to have another knowledgeable person to check your work. It can be easy to get turned around and loose your bearings. A second opinion will help keep you going where you want to go.
Using the Compass with a Map
Now take that road map you brought out with you and spread it out on a flat surface. The top of every map is always North.There should be a Compass Rose somewhere on the map with a pointer toward North.
Lay the compass on the map and let it point North. Move the map under it until the needle is pointing toward the top of the map. You have now "oriented" the map properly in relation to your surroundings.
Now you can see the relationship of the map to the surrounding streets and other local features. It is the same out in the wilderness, only you will be using a topographical map in place of a road map.
A topographical map is one that is designed to show you the local terrain, the lay of the land. It will also show you local roads, structures and locations of mines or other man made features.
A lot of people when they first look at a topographical map get a "deer in the headlights" look about them. Please don't worry, its not that difficult at all.
Topographical maps were just not designed to show you how to drive to Aunt Jane's house and street maps don't show you the terrain features and altitudes of where you are.
Choosing a Compass
Let's see some types of compasses that are around and how they are used. This will help you decide what you want to use in the field.
The compass shown on the left is called a Baseplate, or Protractor compass. It is the most inexpensive kind and works very well in the field. I begin teaching kids with this type.
All good ones are fluid filled which dampens the needle movement and makes it easier to read. The flat base will pivot on the round compass itself making it more accurate to find a bearing.
After orientating the compass toward north, just pivot the base and point the arrow toward what you are taking a bearing of and read the degrees on the compass. This will be the bearing from your present position.
These are inexpensive and are easy to use. The down sides to them are the plastic base can wear, chip, crack or break in time. Rough handling will accelerate that. I like them and use them. I always keep one as a backup, or for a teaching tool while in the field. It also allows someone else to use one at the same time.
The compass I use the most goes by several names. It can be the "Azimuth", "Sighting" or "Army" compass to name a few.
It has a cover that flips up and uncovers the needle. The cover will usually lock the needle in place when closed to reduce any possibility of damage.
The cover then becomes a sighting tool that allows you to easily hand hold the compass and very quickly take an accurate bearing. This is the tool that most people graduate to if you are serious about trekking into the wilderness.
The advantages of this type are the ease of use when backpacking and storing it in a pocket. They do however cost more. How much? That depends on the bells and whistles you want with it.
Go to a good sporting goods or camping store and see what they have, Decide for your selves. There are many types and varieties out there starting at $9.95 up to the hundreds. Remember, they all point north and you can get a bearing off of each one.
An Exercise
Take a look at the compass rose below and look at the cardinal points.
- See if you can learn them by sitting down with a pencil and paper and writing all sixteen of them down in order starting with North.
- Next, try to figure out how many degrees there are between some of the points. Starting with 90 degrees between North and East, determine the amount between North and:
- North East
- East North East
- North North East
- South East
- South West
- North West
