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How to use
a compass (Lesson 2)
Using the compass in interaction with a map
This is the important lesson, and you should learn
it well. It's when you use both compass and map the compass is really good,
and you will be able to navigate safely and accurately in terrain you've never
been before without following trails. But it'll take some training and
experience, though.
I am not covering map reading here, guess you would have to consult other
sources for that, but the lesson will be useful if you have a sense of what a
map says.
First, a quick summary of what you will learn in this lesson:
- Align the edge of the compass with the starting and finishing point.
- Rotate the compass housing until the orienting arrow and lines point N on
the map.
- Rotate the map and compass together until the red end of the compass
needle points north.
- Follow the direction of travel arrow on the compass, keeping the needle
aligned with the orienting arrow on the housing.
Here is our compass again:

The principles are much the same as in lesson 1 but this
time, you are using the map to tell you which way is correct instead of your
intuition.
Take a map. In our first example, we look at a map made for orienteering,
and it is very detailed. Well, not really. We look at a fictitious map I drew
myself, but never mind. To the point.
You want to go from the trail-crossing at A, to the rock
at B. Of course, to use this method successfully, you'll
have to know you really are at A.
What you do, is that you put your compass on the map so that the edge of the
compass is at A. The edge you must be using, is the edge that is parallel
to the direction of travel arrow. And then, put B somewhere along the same
edge, like it is on the drawing. Of course, you could use the direction arrow
itself, or one of the parallel lines, but usually, it's more convenient to
use the edge. At this point, some instructors say that you should use a pencil
and draw a line along your course. I would recommend against it. First, it
takes a lot of time, but offers no enhancement in accuracy of the method.
Second, if you have wet weather, it may destroy your map, or if it is windy,
you may loose it. You should keep your map (preferably in a sealed) transparent
plastic bag, and if it is windy, tied up, so it can't blow away. But most
important is that any drawings may hide important details on the map.
Time to be careful again! The edge of the compass,
or rather the direction arrow, must point from A
to B! And again, if you do t his wrong, you'll walk
off in the exact opposite direction of what you want. So take a second
look. Beginners often make this mistake as well.
Keep the compass steady on the map. What you
are going to do next is that you are going to align the orienting lines and
the orienting arrow with the meridian lines of the map. The lines on the map
going north, that is. While you have the edge of the compass carefully aligned
from A to B, turn the compass housing so that the orienting lines in the compass
housing are aligned with the meridian lines on the map. During this process,
you don't mind what happens to the compass needle.
There are a number of serious mistakes that can be made here. Let's
take the problem with going in the opposite direction first. Be
absolutely certain that you know where north is on the map, and be sure
that the orienting arrow is pointing towards the north on the map. Normally,
north will be up on the map. The possible mistake is to let the orienting
arrow point towards the south on the map. And then, keep an eye on the the
edge of the compass. If the edge isn't going along the line from A to B when you
have finished turning the compass housing, you will have an error in your
direction, and it can take you off your course.
When you are sure you have the compass housing right, you may take
the compass away from the map. And now, you can in fact read the azimuth off the
housing, from where the housing meets the direction arrow. Be sure
that the housing doesn't turn, before you reach your target B! The
final step is similiar to what you did in lesson
1. Hold the compass in your hand. And now you'll have to hold it quite
flat, so that the compass needle can turn. Then turn yourself, your hand, the
entire compass, just make sure the compass housing doesn't turn, and turn it
until the compass needle is aligned with the lines inside the compass
housing.
The mistake is again to let the compass needle point towards the
south. The red part of the compass needle must point at north in the
compass housing, or you'll go in the opposite direction.
It's time to walk off. But to do that with optimal accuracy,
you'll have to do that in a special way as well.
Hold the compass in your hand, with the needle well aligned with the orienting
arrow. Then aim, as careful as you can, in the direction the direction
of travel-arrow is pointing. Fix your eye on some special feature in the terrain
as far as you can see in the direction. Then go there. Be sure as you go that
the compass housing doesn't turn.
If you're in a dense forest, you might need to
aim several times. Hopefully, you will reach your target B when you do this.
At this time, you may want to go out and do
some training, so you could check out some suggested
exercises.
Unfortunately, sometimes, for some quite often, it is even more
complicated. There is something called magnetic declination. And then,
for hiking, you wouldn't use orienteering maps. And this is the issue for lesson 3.
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