Subject: Re: Magnetic Pole Navigation

From: [email-masked] (Hal Lillywhite)
Date: 16 Sep 1994 12:49:10 -0700

Unless you are right on top of the magnetic pole a compass will
work.  It may point east, west, or even south in the vicinity of the
magnetic poles but the important things are:

1.  The compass points in a consistent direction (it will unless you
are going around the pole), and

2.  You know how to use it, including how to compensate for
declination.

3.  You know other navigation things like paying attention to where
you are, terrain etc., how to read a map etc.

Here is something I posted previously on rec.backcountry on how not
to get lost:

How can a person avoid getting lost?  A good question and there is
probably no simple answer.  However, there are some tried and true
techniques which help.  I think it is helpful to divide this subject
into two rather broad categories:

I.  Developing a "feel" for the land, a sort of mental map.  I
think we all do this more or less with our home territory.  We know
which streets intersect and approximately how they relate to each
other.  Most of us have little trouble finding our way between our
homes, work, friends houses, etc.  We usually have a sort of mental
map of this familiar terrain.  When we visit Joe we just go to his
house, we don't have to think about going so many blocks one way
then looking for street names etc.  When we arrive in unfamiliar
surroundings it helps to quickly start developing something similar
for them.

II.  "Formal" navigation using compass, altimeter or other aids
(including some natural ones).  This is the technique which allows a
person to go from one place to another based on information from a
map or directions from someone else.  This can be anything from
following a road map to an unfamiliar town to a complicated cross-
country hike with many intermediate landmarks requiring compass
bearings etc.  This type of navigation seems less natural and
usually requires more effort to learn.  However it is necessary in
unfamiliar territory.  It can  also help us more quickly form the 
"mental map" of the first type of navigation.

In the following list I will not attempt to distinguish which
techniques fit which category.  Many of them fit both.  The best
navigators use both anyway.  It is helpful to combine them, eg. use
"formal" navigation to help develop a mental map and the mental map
to supplement the formal techniques.

1.  Simply be alert to your surroundings, especially as you travel.
Most of us use a variety of clues to help know where we are.  Most
of these clues are visual although sounds and even smells can help.
(The rotting animal carcass can provide a very memorable smell to be
recognized on the way back).  The person who pays attention to
trees, rocks, hills, streams, etc. will have a great advantage over
the guy who simply looks at the trail in front of him.  Try to look
at features from several different angles as you move.  Try to put
together in your mind how different features relate to each other
and to your route.  (Of course being alert to surroundings also
enhances your enjoyment of the outdoors, the reason most of us are
there in the first place.)

2.  Try to keep track of your directions and associate them with
the territory around you.  For example, notice not only the odd
shaped hill, but notice that it is northeast of you and runs 
approximately east and west.  Try to be aware of the direction the 
trail is going.  Notice that that hill is ahead of you on the trail,
then off to the right a bit as the trail turns.  A compass is handy 
to keep track of the direction the trail runs.  Again you are trying 
to form a mental picture of the territory and how it is oriented.  
Some of us are better at this than others but I think we can all 
improve with practice.

3.  Occasionally look behind you to see how the territory will look
on the return trip.  Be especially diligent at all junctions or 
anywhere else the trail is not glaringly obvious.  All those odd tree 
branches and readily recognizable rocks will look very different from 
the other direction.  

4.  Learn to use a compass reasonably well.  You may not need to
take a bearing to within 2 degrees but you should be able to figure
out which way is north.  This means understanding declination (unless
you will only be in areas where declination is less than about 5
degrees).  Learn to go back the direction you came from using your
compass (see "back bearing" below).

4a.  If you are likely to travel after dark or in a whiteout, learn 
to use the compass *well*.  Learn to follow a bearing, a back
bearing, detour around something and get back on route, etc.  Learn
how accurately you can follow a bearing under different conditions 
and how to compensate for that inaccuracy (offset bearings, landmarks 
etc).  If your night or whiteout travel will be in mountainous areas
get an altimeter and learn to use it (and what its limitations
are).

All compass, altimeter, and map techniques are best learned by
practice in familiar surroundings under good conditions.  It's a bit
late to learn when you are in a howling blizzard.

5.  Use the compass *long before* you get lost, including at the
trailhead and at several intermediate points.  The object is to help
develop a "feel" for which direction you are traveling and to learn
which way you go out so you know which direction you must go to return.  
It does little good to know which direction is which when you are lost 
unless you have some idea of which way to go.  (Well, let's see.  
North is that way, South is opposite and East is that way.  But which 
direction is the $#^%^$@* car?)  In fact it is a good idea at the
trailhead to get out your map and compass and orient the map with
the terrain.  Put the map so that map north is true north and look
around.  Identify the direction you plan to travel and as many
landmarks as you can.  If you don't have a map, at least do this
with the compass and look at terrain features, the direction the
trail goes, etc.  Be sure you know which direction *you* are facing
when you look at landmarks.

6.  Learn to recognize nature's direction indicators.  For example
moss does not always grow on the north side of trees but it commonly
does grow on a preferred side which varies with location and depends
on the prevailing winds.  Be aware that these indicators may change
from place to place as the prevailing winds change.  This can occur 
in quite short distances if hills affect the wind.  (Of course in
places like the northwest, moss can grow on all sides of the trees.
Maybe you can look for which side has the thinnest coat of moss.)
Tree branches can also be affected by prevailing winds.  The sun and
shadows can also give indications of direction if you take time of
day into account (remember to account for daylight savings time).
These indicators are usually not very precise (except for the north
star or astronomical readings taken with specialized equipment).
However they can help you keep a general idea of which direction is
which.  If the moss on trees was to your left and suddenly you notice 
it is toward you, maybe you changed direction without noticing.  Check 
your compass or otherwise find out what happened.

7.  Unless you are certain you will *never* leave the trail, learn
to use an offset bearing and linear landmarks.

8.  Learn to read a map.  Try to carry a good map of the area you
are in.  However even if you don't have a map with you the
experience of knowing how to use one will help with your ability to
construct your own mental map of the territory.

9.  *Never* place all your trust in someone else.  Spouses,
"knowledgable" friends, SO's, party leaders all make mistakes.  Try
to keep track of where you are yourself.  If you feel lost ask the
leader for help or for time to orient yourself.  This will promote
safety on that trip and help you learn for the times you are on your
own.  If the leader can't or won't help don't go with him/her again 
(if you get back that time).  Good leaders recognize that (a) they 
make occasional mistakes and a crosscheck is useful and (b)
occasionally people get separated from the group and they better
have some idea where they are.  The only exception I can think of is
the rare case when speed becomes important to safety (eg. you gotta'
get off the mountain before the storm hits).  Then the leader may be
justified in asking you to just follow.  (He should, however, remain
open to questions while you move.)

There are a couple of tricks which make use of the compass easier.

I.  Shooting a "back bearing."  The compass is handy for going back
the way you came from.  To use this you need to set the "direction
of travel" when you go out.  (See directions which come with your
compass, I won't attempt to describe it here.)  The usual technique
is to add or subtract 180 degrees from that bearing to find the
return bearing.  It works if you don't make a mistake but is
unnecessarily complicated.  Even the best of us can make simple
arithmetic errors, especially when we're tired, cold, and in a
hurry.  A much simpler technique is to simply turn the compass
around and pretend the south needle is the north.  This always gives
an exact reversal of direction.

II.  Offset bearings (also known as "aiming off").  It's nice to know 
that if you travel for 5 miles on a bearing of 213 degrees magnetic 
you will be back at the trailhead.  The problem is that most of us 
are doing very well if we can stay within 3 degrees of a bearing, 
even worse in anything but open country.  In 5 miles a 3 degree error 
will put you off course by a quarter of a mile!  You will probably 
miss your target and if you come to the road you won't know which way 
to walk.  The solution is to make a deliberate error in a known 
direction.  Determine how accurately you can set and follow a bearing, 
then aim that far to a given side.  Pick a linear landmark (road, 
stream, etc., also known as a "handrail") and when you arrive at it 
follow it back to a known location such as your car or a recognizable 
stream crossing.  This is the recommended technique, for example, to 
get off Mt. Hood in a whiteout.  In that case, people can aim to the 
east or west of the lift line.  Then when the altimeter (or a good 
guess) says they are well below the top of the lift they simply turn 
the appropriate direction, find the lift, and walk down under it.  If 
somebody tried this without knowing which way to the lift he could 
easily go the wrong direction and end up either on White River Glacier 
or among the cliffs of Zig-Zag Canyon, both potentially dangerous 
places.

And one trick to make your maps easier to use:  Draw north-south
lines on them and declination lines (that is, lines running magnetic
north-south as well as true north-south).  These lines should be
about an inch apart so when you place a typical compass on the map
there is always a north-south line and a declination line under it.
This is much easier if you have access to a drafting table.

This is not intended to be a comprehensive course in cross-country
navigation.  It is intended to give some suggestions.  You won't
learn navigation by reading anyway.  Practice, practice, practice.
When you try something and it doesn't work, try to figure out why
and what you can do better next time.  Try to find someone good at
navigation and spend time with him/her in the field watching, asking
questions, and learning.  How much of an expert you need to become 
will depend on what activities you engage in but be sure your skills 
are up to your activity.  If in doubt try something easier and save
that particular trip for when you have improved.

Finally, be sure somebody knows where you are going, when you plan 
to return and who to notify if you don't come back.  If all else 
fails and you get lost (or injured) nobody will come looking for 
you until the proper authority (usually the sheriff's dept.) is 
notified.  Even when the search starts it will be much more
effective if searchers know your destination, not just where you
parked your car.

Even if you get very good with all these techniques there is no
guarantee you will not get lost.  If that happens, first sit down
and relax a bit.  Sometimes just a pause will allow you to reorient
yourself.  Your mind will be much more effective if you can remain
calm.  Get out your compass and see which way is north.  (You do
have one don't you?  And you did orient yourself at the trailhead,
right?)  If you have no compass try to find a natural direction
indicator (North Star, drive a stick in the ground and see which way
the shadow moves etc.).  Look around for distinctive landmarks (but
be careful before you decide that that hill is the same one you saw
from camp.  Don't let similar hills fool you.)  In the best case you
may discover where you are and be able to return without problems.
If this doesn't work consider yourself lost and act accordingly.