CHARTING A COURSE
USING A COMPASS ALONE
[Nyerges has been
teaching outdoor survival skills and preparedness since 1974. He is the author
of “How to Survive Anywhere,” “Guide to Wild Foods,” and other books. He can be
reached at www.SchoolofSelf-Reliance.com,
or Box 41834, Eagle Rock, CA 90041.]
Let’s say it’s dark, or overcast, or you’re traveling in
thick woods. You don’t have a map, but
you have a compass. You’re not traveling in a straight line, but going here,
going there, finding out what’s out there.
There’s a way that you can take records of your travel, and
then chart a direct path back to your camp or car. It’s not that difficult, but it does require
a compass, and a pen and notebook.
Let’s say you’ve driven to a remote area in the forest and
you want to explore a large area for possible camp sites. You set out at 27
degrees, and you walk for 20 minutes.
You make two columns in your notebook, and you record 27 in the degrees
column, and you record 20 in the time column.
Then, you decide to change directions, and you head out at
150 degrees. You write that down in the “degrees” column. You walk for 30 minutes before you pause, so
you record 30 in the minutes column.
You continue this way for the rest of the day, always
recording the degree in which you walked, and the amount of time you walked in
that direction.
Now, before we get too far along, let’s review (for you
beginners) how to determine what degree you are walking. With your orienteering compass, you point the
“direction of travel” arrow – which is the printed arrow on the housing of the
compass -- in the direction you are traveling.
So far so good? Now, you turn the
round dial until the printed arrow is directly over the north end of the
needle. OK? That’s pretty basic compass use. Sometimes we refer to that step as putting
the dog in the house. The printed arrow
looks sorta like a dog house, and the magnetic needle (the “dog”) must be kept
aligned with the “doghouse.” As long as
you keep the dog in the house, and follow your “direction of travel” arrow,
you’re accurately traveling at whatever degree you’ve decided to walk in.
Obviously, for this system to work well, you need to walk in
fairly straight lines. In fairly rugged
terrain, this system might not be practical or possible.
So, let’s say you’re done exploring for the day, and your
notebook contains 6 entries for degree traveled, and 6 entries for amount of
time traveled.
With that information, you are now going to create a simple
map to determine a straight path back to your camp or wherever you started
from.
Let’s take a look at the notes you took, in the example, and how to turn
those notes into a map.
Here is an example of what your notes might look like.
DEGREE
OF TRAVEL
|
TIME TRAVELLED
|
27
|
20
|
150
|
30
|
240
|
20
|
180
|
20
|
285
|
30
|
Remember, this is just an example, and in the example, we
have kept the units of time all divisible by 10 minutes. In real life, your units of time would likely
be much more diverse.
Using your notebook, or using sticks on the ground, you will
turn the units of time into linear lengths. So, for example, each ten minutes
of time traveled will be one inch. It
doesn’t really matter whether you make each ten minute segment represent one
inch or five inches or the length of your finger or the length of your Swiss
army knife – just be consistent with whatever unit of conversion you use.
So let’s say you are going to use sticks to create a map.
For your first 20 minute leg of your journey, you cut a straight stick 2 inches
long (10 minutes = one inches). Lay the
stick on the ground and align it at 27 degrees, your direction of travel.
Your next leg of your journey was 30 minutes, at 150
degrees. So you cut a stick that is
three inches long.
From the leading end of the first stick, set down your three inch long
stick and align it at 150 degrees. So
far so good? You are creating a map of
your journey.
Next, you cut a two inch stick and align it at the end of
the last stick at 240 degrees.
Next, cut another two inch stick and align it at 180 degrees
from the end of the last stick.
Finally, you cut a stick three inches (30 minutes = 3
inches) and set it at the end of the last stick at 285 degrees.
OK? You have just created a visual map of your journey using stick, converting time
into linear lengths. When you have
completed your stick-map, you now place your compass at the end of the last
stick (which represents where you stopped, and decided you wanted to go home),
and point it to your starting point.
That is your direct line back to your camp. Put the dog in the house on your compass, and
simply follow the direction of travel arrow back home.
And because you have chosen each 10 minutes of travel time
to represent one inch, you can just measure your straight line back to your
camp to get a good idea of how long it will take you to get home.
From my reckoning, it appears that you can now walk straight
at 30 degrees, for about 35 minutes and you’ll be back in your camp! Not bad, considering that your entire journey
so far took two hours.
Now, we did not discuss the variables that come with uneven
terrain. That is, if you had a lot of
uphill travel, you probably couldn’t cover as much terrain in 10 minutes as you
could if the ground were flat. So you
should record these terrain changes in your notebook. If you walked for 20 minutes, that would
normally represent a two inch stick. But
if the terrain was very sharply uphill, you wouldn’t have been able to cover
the same distance in the same time. You
would estimate, and probably use just a one inch stick for that leg of your
journey. You should also record any
changes in the speed of your hiking, though this works best if your speed is
more or less the same.
There’s a bit more to this, so please come to one of my
Orienteering workshops when you can.
See the Schedule at www.SchoolofSelf-Reliance.com.
Also, get a copy of each of these following books:
“The Green Beret’s
Compass Course,” by Don Paul, 2006.
The technique described in this article was based on his book, available from Amazon.
“Be Expert with Map
and Compass” by Björn Kjellström
is still one of the best overall guides to map and compass use. Available at
Amazon.
“How to Survive Anywhere” by Christopher Nyerges includes a short
section on navigation.
No comments:
Post a Comment