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Following a Compass Bearing
Steve Gregg, BAOC
My biggest weakness as an orienteer, by far, is following accurate
compass bearings through a featureless forest or across a broad
plateau. Fortunately that is a skill we get the opportunity to practice
a lot in the Chicago area. Very little of our terrain has reentrant,
spur and other easy-to-read topographic features that make orienteering
fun in more rugged areas of the world. In such areas, accurate compass
work is not needed to navigate. In fact, it is common in some terrain
to leave your compass in your pocket and navigate only by the distinct
features you see around you, following the orienteering map as you
would a street map.
This past summer, though, I ran on several maps where accurate
com-pass work was essential to even complete the course. In particular,
at the Western Canadian Championships in Alberta there were several
completely flat areas of fairly dense, featureless forest, and to
find your way from control to control, accurate compass bearings
of 150 meters or more were essential. Burton Creek was like this
to some extent (although that map had more recognizable detail between
controls, so it was easier to readjust your bearing along the way),
and the advanced courses at Big Basin required very accurate compass
work most of the way as well (which is why it took me over three
hours to complete the Blue course). So I've been trying to learn
how to get better at taking precision bearings, and have learned
a couple of things which I will share below:
- Use a base plate compass that can be set; a thumb compass just
doesn't allow as much precision as a base plate compass.
- Hold your compass completely flat and keep it straight out in
front of you. I've found that if you tilt your compass up toward
you to look at it, the needle can stick a just a bit and throw
your bearing off by 10° or so. Also, it's easier to see exactly
where the direction arrow is pointing if you have the compass
right in front of your face, rather than off to one side or the
other.
- In theory, taking precision bearings is an easy process. You
just
- set the compass to the desired route on your map,
- lift the compass and properly orient yourself,
- pick some object in the distance that the direction arrow
is pointing toward, and
- run to that object.
- Then repeat those steps as often as necessary.
In dense forest, however, the trees in the distance will all appear
identical, and when you look down and dodge from side to side to
avoid obstacles, you may lose sight of your objective when you look
back up again. So try to select an objective that is unique and
distinct: a big tree, a prominent branch, or a lighter color.
Another secret in running an accurate bearing is to alternate directions
when you have to deviate from the straight-line path. If you do
this, hopefully the corrections you make will cancel each other
out and you will end up on your desired bearing. I discovered this
summer that I am definitely "left-footed." That is, my
natural tendency is to always veer left to avoid obstacles,
and as a result I am often way off to the left at the end
of a long bearing. Now that I am aware of this, I am trying to force
myself to go right half the time, but it's hard!
Of course, the best solution to the problem is to not have to rely
on such accurate compass work in the first place! Given the choice
between taking an accurate 150+ meter bearing straight to a control,
or going out of the way somewhat to get to a closer attack point,
I'll run the extra distance every time. But sometimes there's no
choice - you just have to follow your compass and hope for the best.
Good luck!
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