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Navigation for Survival

The wonders of modern technology are all fine and dandy, with super accurate compasses and GPS gizmos making navigation as simple as can be. However, what would your situation would be if, in the middle of nowhere, you come to the realisation that your GPS unit has gone on the fritz/been crushed underfoot/run out of batteries, and your trusted compass is lost/broken/left at home because you were trusting in your GPS?

Alone, in unfamiliar territory, without your basic compasses, maps, communication equipment, unless you have some idea of 'survival navigation', you are effectively in deep and smelly region of LOST.

Such situations call for innovative approach - what the psychologists call "lateral thinking". With a degree of natural cunning, you can utilise various odds and ends,plus celestial bodies (no, not the kind in dodgy magazines - the ones in the sky) to find your way. This requires some knowledge and application to get right, but even Cub Scouts know the basics and can navigate without a compass with reasonable accuracy.

The first step is to improvise a compass. This can be done in various ways, but each require a ferrous metal object such as needle, pin, nail razor blade,metal rod or similar, and a suspension system. The simplest way to magnetise your rudimentary compass needle so that it is attracted by one end to magnetic North just like and compass needle,is to stroke it with a magnet in one direction only. If you stroke towards the point of your needle, the point will indicate North (FIG.1).

Failing the availability of a magnet, stroke your compass needle with silk. Both these methods will need to be repeated regularly to maintain the magnetism of the compass needle.

Lacking silk or a magnet, you can also magnetise a needle, or similar, using a battery of 2 volts or more, and some insulated wire, preferably copper.

Coil the wire around your soon-to-be compass needle, and connect it to the terminals of your battery for about 5-10 minutes. It is important that the needle is insulated from the wire, so, if you only have bare wire insulate the needle by first wrapping it in paper thin card or similar (FIG.2).


A razor blade can be magnetised in the same way, or by stropping it (be careful here) on the palm of your hand.

It is also possible to magnetise metal with a hammer and the earth's magnetic field (FIG. 3): Place the nail/needle against the ground aligned with magnetic North/magnetic South, the raised end pointing South in the Northern hemisphere, North in the Southern hemisphere. The angle that the earth's magnetic field enters the ground (angle A) - the angle to which you elevate the rod - unfortunately varies from place to place; it is 68 degrees in England, but between 62 and 80 degrees around Europe.

This angle of elevation should be as accurate as possible, though good results can be achieved with up to 10 degrees error either way. Hit the positioned metal with hammer, and with trial and error,and time, you should be able to produce a magnetised compass needle this way.
Of course, you will need to suspend your compass needle so that it can swing freely. This can be done by tying it onto the end of a thread - beware of kinks and twisting in the thread, and be sure to balance the needle carefully (FIG.5).



For more accurate results, float your improvised compass needle, using paper, bark, grass etc. as a floating base on a still pool of water, eg. a puddle, full mess tin of the like. Be sure to protect this compass from any wind (FIG.6).



You will need to identify which end of your compass points North and to mark it for easy recognition. Check it against other systems of finding North. Be warned: gross errors may be caused by nearby metals, such as tanks, knives, and metal deposits underground.

If you lack the materials to make an improvised compass, you can rely on the sun, moon and stars for guidance.

Everyone knows the sun rises in the East, sets in the West and is due South at local noon (or North if you are in the Southern hemisphere). To find which hemisphere you are in (boy, are you lost!) watch the shadow's movements for a few moments to establish East and West.


If you have an analogue (non digital) watch, the following method of finding the North line works well. (If yours is digital, draw and analogue watch face showing the time on your digital in a piece of paper and use this).


Hold the watch horizontally with the hour hand pointing at the sun. If your watch is set on GMT or true local time, bisect the angle between the hour hand and 12 to give the North/South line. In the Southern Hemisphere point the 12 at the sun and bisect the angle between this and the hour hand to get the North/ South line (FIG. 8.
)



While reasonably accurate, this is a fairly rough and ready method of finding North/South, and it gets less precise the nearer you are to the Equator. In addition, it relies on your having a timepiece, knowledge of true time and a visible sun.

 Lacking all, or any of these, the system fails, but as long as there is enough light to cast a shadow, and you have a stick or similar object (even your oppo standing still will do) the sun can still give you the North/South line. A straight stick about 3 feet long is ideal, and you will need preferably flat, clear ground to work on.

The quick method can be used on the move, takes about 15 - 20 minutes as you take a rest, but is not terribly accurate: Stick the pole upright in the ground and mark where the tip of its shadow falls. Wait at least 15 minutes, then mark where the tip of the shadow now falls. Join the two points to give your East/West line. Your North/South line naturally bisects this at right angles. (FIG.9)


The more time consuming, though more accurate, method uses the same stick upright in the ground, but can take all day (your oppo may resent being used for this method): Mark the first shadow in the morning at its tip, then draw a perfect arc (use string tied to the base of the pole for best results) with the pole as the centre point.

When the tip of the shadow falls reaches the arc again in the afternoon, mark this spot exactly. Join the morning and evening marks to give the East/ West line, and, again, the North/South line bisects this at right angles. In both methods the first mark is West (FIG.10).

At night you lose the sun (never!), but you will have the moon and the stars to guide you as they have guided travellers for centuries.
The moon, having no light of its own, is seen by way of light reflected from the sun, because the moon's lighted area varies as it waxes (grows larger) and wanes (diminishes), this, combined with its rotational rate, can give a rough help to your navigation. Cutting the technical explanation, if the moon rises before sunset, the light side of the moon is on the West. If the moon rises after midnight, the illuminated side is to the East.
As a rule of thumb, stars rise in the East and set in the West, but knowing, and being able to identify, some simple to recognise constellations will give you and even more accurate fix on your North/South line.


In the Northern hemisphere, we are lucky to have the Pole Star sitting over the North Pole with a variation of only about 2 degrees. This star is extremely useful for navigation, and can be found using the obvious constellations of the Plough (also known as the Dipper) (A), Cassiopeia (B), and Orion (C) (FIG.11).

The Plough and the Cassiopeia never set. While all three constellations seem to rotate around the Pole Star, Orion is the most useful if you are near the Equator.

An imaginary line drawn from the 'tail" of the Plough to the lowest of the points of Cassiopeia, goes through the Pole Star (FIG.12) while the central peak of the 'W' formed by Cassiopeia points to the Pole Star.

The two lower stars of the Plough also point to the Pole Star approximately four times the distance between the two stars. Orion rises above the Equator, and can be seen in both hemispheres (FIG.13) rising due East, and setting due West. The three stars forming the 'belt' point East/West.

Finding South in the Southern hemisphere is achieved by finding the Southern Cross. This is done by first locating a dark patch in the Milky Way (no, not the chocolate bar, the band of millions of distant stars) which is called the 'Coal Sack'. On one side of this is the Southern Cross, a constellation of five stars, while on the other side are two pointer stars. Make sure you do not get confused by other nearby cross shaped constellations (FIG.14).

By drawing an imaginary line five times the length of the Southern Cross's long axis along the same line towards Earth, you reach a point in the sky above the South point of the horizon. Mark a reference point here for your South point (FIG.15).

By setting up two sticks, or by using the sights of a securely positioned rifle, you can sight on a star to note its apparent movement over a few moments (FIG.16).



In the Northern Hemisphere: if the star seems to fall, you are facing West; if the star seems to curve flatly to the right, you are facing South; if the star seems to curve flatly to the left, you are facing North.

Although this is a rough and ready system, it can be made to work with any star other than the Pole Star. In the Southern hemisphere, the directions are reversed.
Should you have zero equipment, and 100 percent cloud cover day and night, the best advice is to sit and wait either for better weather or for a rescue party!

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