Find your way with the help of Coghlan's Map Compasses! We want to help you become confident in your hikes and orienteering adventures, be able to understand and provide direction based off of compass readings and interpret distances based on multiple scales.
For beginners and seasoned navigators alike, this guide is here to help you get from Point A to Point B with nothing but this trusty compass and a pocket map at your disposal.
Ordinarily we use the words “North”, “South”, etc. unconcernedly, however, we must realize there are two kinds of North, ie. Geographical North and Magnetic North.
Geographical North is established geographically and it is common to all over the world. The circles of longitude of a map are drawn in correlation to the geographical poles and the lines show the direction of the Geographical North. The direction of these lines is different from the direction that the magnetic needle points to. On an ordinary map upside is the direction of the Geographical North and downside is the Geographical South. Accordingly, right side and left side are East and West respectively. The magnetic poles are close to the geographical poles, but are not coincidental. The angle between the straight lines pointing from the place of observation to the geographical and magnetic North poles is called Variation or Declination of the places, Figure 1.
The variation differs from place to place in the world. The lines of equal variation are very irregular, however, topographical maps of each place give the local variation. When you say a direction and such degrees, you must either subtract or add the local variation depending on which side of zero declination line you are on for getting the geographically correct degree for the direction. For obtaining the true map bearing read the bearing on your compass and if the local variation is Western, subtract the variation from the reading, if it is Eastern, add it to the reading. However, it is more practical for you to use the bearing you get when you set the Magnetic North as 0°.
Suppose you can see and object, say, a lake. If you can see the lake all the way while you are walking, there is no problem. However, on the way to the lake you may have to go through such a place as woods, hollows, etc. from where you cannot see the lake. In such case you may lose direction of the lake and your compass becomes very useful.
For instance, in Figure 2 the direction of the object is 320° (for expressing it exactly you must adjust the local variation as explained formerly. However, as long as you understand the meaning of variation you can say the direction of the object is 320° from the magnetic North).
For going to the destination shown on a map merely find the present place, direction of the destination and the magnetic North.
Then turn the rotating ring and make the arrows in the compass capsule parallel to the magnetic North lines you drew in step 1. (At this stage you do not have to mind the position of the magnetic needle). Next, hold your compass and turn yourself slowly until the North end (the luminous end) of the magnetic needle becomes parallel to the arrows in the compass capsule, Figure 4. Now proceed toward the direction the arrow of the travel line points to by keeping the magnetic needle parallel to the arrows of the compass capsule. Simply keep going to this direction until you reach your destination. When you arrive at the first destination repeat the same procedure for going to your final destination. While you are proceeding toward the destination you have to make sure of the direction by looking at your compass and go as straight as possible. If the deviation to right or left from the correct course is large, the error at your goal becomes large.
Locate yourself on a high point from where any two distinctive features of the landscape are visible. The two distinctive features must be shown on the map. Suppose you can see a mountain A on the left and a lake B on the right side. Point the index line (arrow) toward the mountain A. Then rotate the rotating ring and set “N” of the dial to the North end of the compass needle. Place compass on the map and adjust the map so that the magnetic North line on the map becomes parallel to the magnetic needle and the N-S lines in the compass capsule. By keeping the state slide the compass on the map until one side of the scale points to the mountain A on the map and draw a line, Figure 5. Then, turn yourself to the lake B and repeat the same procedure and draw a line. The point of intersection of these two straight lines is your present location on the map, Figure 6.
Many books on compass reading and orienteering are in print. We recommend reading them and/or taking a course to refine your compass and map reading skills.