| Compass Bearings |
| A bearing is a 3 digit angle measured clockwise
from north. It is a way of indicating direction without ambiguity.
We usually speak of taking a bearing between 2 points, or the
bearing of the pub from the church. We may need to use a bearing
when the weather conditions are poor, or the surrounding landscape
is unfamiliar or featureless. Then navigating by the map alone
may not practical, and we may have to rely on the compass to
tell us the direction in which we wish to travel. You may also
need to take bearings when trying to pinpoint your position
on the map by triangulation. Either way the process is quite
simple once you get used to it. (Note: For accurate bearings
you will need to take into account the magnetic variation, but
here I will ignore this for simplicity).
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Darren Dowling
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Connected is a central area that provides links to obtain
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| Taking a Bearing |
Darren Dowling
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To take a bearing between two points follow these steps (again
I will assume we are using a common 'Silva' type compass).
Note the two alternative methods at steps 1 and 4:
- Leave the map as it is (in any old direction) OR
[Set up the map so that it is facing north.]
- Locate the point at which you wish to walk from, point
A, (i.e. usually your current location) and the point you
wish to walk to, point B.
- Align the compass edge (assuming it is rectangular) so
that it forms a line between these two points. Note that
the compass should be facing in the correct direction (the
direction of travel arrow should be pointing towards the
place you want to go, the bottom of the compass is placed
at your current location). If the compass is not long enough
to do this, use a ruler or similar to join the two points
and place the compass alongside this. The compass does not
have to have the direction of travel arrow touching the
two points (i.e. parallel lines will have the same bearing).
- Rotate the dial so that the faint vertical lines on the
dial itself align themselves with the vertical (blue) grid
lines on the map OR [Rotate the dial so
that the red marker on the bottom of the dial matches up
with the red end of the north-south pointer]
- You can now pick up the compass if you wish. Read off
the number on the dial against the direction of travel arrow
(there will usually be a small black marker to help you
in this). This 3 digit number is the bearing of B from A.
(Do not worry too much about the 3 digit business. If the
angle marked is 30° it should be called 030° but
this does not really matter too much). As always be careful
about how many degrees each line on your compass represents.
There are many different types with different markings,
but usually each small line is worth 2° with intervals
of 20° marked on the dial in writing.
- If you wish to walk in a straight line from A to B, simply
keep an eye on the compass and follow the direction of travel
arrow. You must take care to ensure that the two red pointers
(north-south and red marker on the bottom of the dial) remain
aligned at all times.
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| Important notes on using bearings |
Darren Dowling
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When following a bearing (i.e. attempting to walk in the
direction indicated by the compass) do not just try to look
at the compass and walk in a straight line. Even when trying
hard to walk in a straight line on flat ground there is usually
a natural tendency to deviate slightly (normally off to the
right for right handed people) and in any case, the landscape
is hardly ever nice and flat. There will always be reasons
to deviate off your intended path, that clump of trees, those
holly bushes, that mountain spur. Even with flat ground and
good 'seeing' it is very tiring to continually check your
progress against the compass.
The best thing to do is to look along your bearing (taking
care that the compass pointers are aligned as best you can)
and notice a landscape feature that lays along that path (e.g.
"that large gnarled oak tree over there"). Then
you can effectively forget about the compass and just make
your way to that feature along the best possible root. Take
regular sightings of the feature in case you lose sight of
it during your 'detours'. When you reach the feature, simply
take the same bearing again, (i.e. sight along the compass
again) and repeat, looking for a prominent feature. With practice
this is a very quick, yet still accurate method of travel.
Of course it is not very effective in very poor weather conditions,
at night, or in featureless landscapes, and there you will
have to rely on regular (frequent!) checks on your compass.
But for most situations it is effective.
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