A few elements come into play when determining your route.
Picking out a route, be it for march, scouting, or movement on the field of battle relies upon these four things. It first assumes you know where you need to go, or at least what direction you need to go. Ideally, you will have a compass with you when scouting or moving alone. As a unit, your squad leader should have one. Direction can also be 'rough estimated' by using the sun and stars.
A map comes in handy not only in plotting where you have been, but where you need to direct yourself in the near future. It will also assist in picking out places to move through or to avoid entirely. Functionally though, several guidelines come into play when moving by day and night.
Most of these sections assume the individual is alone or in a small group, larger formations will use the same basics, but move in different manners (formations).
How to Use a Compass
The nomenclature of a compass is displayed below in Figure 34 from FM 21-75.
"The standard type lensatic compass may be held with the thumb through the holding ring, supporting the compass with the first two fingers (see figure below). Adjust the eyepiece until the figures in the dial can be plainly read through the lens. The arrow at rest points to magnetic north. The angle any line makes with the north line, measured clockwise from the north point, is the magnetic azimuth of that line."
"Hold the compass as directed above. Stand so that the arrow is under the stationary index. The line of sight is now magnetic north.
Turn the body to either the right or left. The number now under the stationary index is the magnetic azimuth of the new line of sight."
click for larger
Determining an Azimuth to an Object on the Ground
To determine the azimuth of any object, align the rear sight and the front sight upon the object. Let the dial come to rest. Read the azimuth under the stationary index.
Determining an Azimuth To an Object on a Map
To determine the azimuth of an object on a map, draw a fine line connecting your position and the object. Orient the map. Place the compass on the map, compass cover towards the object, with the hair line in the lid directly over the line drawn on the map. The reading at the stationary index now indicates the desired azimuth.
To March in a Desired Direction
Look through the lens and turn the body until the required azimuth is read. Pick out a reference point in the line of sight. March to the reference point. Repeat with successive reference points as often as necessary.
Determining Direction Without Compass
By Watch & Sun
Within the latitudes of the north temperate zone, which include the continental lines of the United States, the following method, correct within 8 degrees, may be used from about 0600 to 1800. Set your watch at correct sun time for that locality, then hold it horizontally, face up, and point the hour hand at the sun; a line from the center of the dial passing between the hour hand and 12 o'clock (bisecting the smaller arc) points south. Look along this line and pick out some object on the ground.
By the Stars
The two stars at the top of the bowl of the Big Dipper, known as the "pointers", indicate at any hour the position of the North Star. The Big Dipper revolves around the North Star and the pointers continue to indicate its position. To locate the North Star, look out for a distance equal to five times the distance between the pointers in line with the pointers in the direction in which water would flow out of the dipper.
Another constellation, Cassiopeia, may assist in locating the the North Star. The five principal stars of Cassiopeia form a "W". This constellation is opposite the North Star from the Big Dipper. Note on the chart that the distance between the North Star and Cassiopeia and the North Star and the Big Dipper are about the same. Cassiopeia also revolves around the Big Dipper. The top of the "W" generally points in the direction of the North Star and the Big Dipper. The direction of the North Star is true north.
The "Joe Method"
Railways, smoke of cities, towers, telegraph lines, and the prevailing wind furnish other means to determine direction.
Reading & Using a Map
On nearly all military maps, north is a the top of the map. Your map is said to be "oriented" when the north and south points on your map match that of the ground. Your map should always be oriented when using it, not doing so is akin to reading a book upside down or sideways.
There are two ways of orienting a map. By inspection and by using your compass.
Inspection requires that you align your map according to features on the ground that you can identify. The map is rotated until it matches the terrain.
You may also orient your may by compass. Turn the lid back and down and place the hair-line along the magnetic north-and-south line of the map, the lid lying to the north. Turn both the map and compass, keeping the hair line over the magnetic north-and-south line on the map, until the compass needle points in exactly the same direction as both lines. Your map is then oriented.'
Maps often be marked or need to be marked with features or locations of troops. The following key provides common symbols used.
Preparation of Route
Decide where you must go to accomplish your mission
Study the map until you can picture in your mind the ground you must traverse.
Note the probable danger areas such as crossroads, villages, and high points.
Make a plan of procedure.
Select a route following low ground, hollows, and woods.
Pick intermediate observation points.
Determine the compass direction at the start and a reading for each change of direction.
Moving by Day & Night
Choose your route carefully by day and night. Make all possible use of screens, background, and shadow. Note Route 1 below for for daylight. This assumes that there is fairly good undergrowth and shadow concealment against ground observation. Under favorable circumstances the enemy can see as much as 100 yards into an open wood.
In this latter case, travel farther back from the edge. Woods with medium undergrowth also furnish numerous good observation points and cover. Heavy undergrowth is an obstacle to movement, and where rapid movement is more important than full concealment, movement by bounds along the outside edge and in the shadow of the woods may be possible.
Where only a hedge or fence is available, and you can do so, move in the shadow. The less growth available, the more the necessity for crawling and running. In addition, movement over open ground is disclosed by tracks.
click for larger
Note Route 2 in the first image above for dark night. The reason for this is that it is more difficult to walk quietly in the woods at night, easier for the enemy to surprise you. A dark night furnishes the shadow, and the route is chosen to give you background and keep you off the skyline. Light discipline is essential. On bright moonlight nights, the shadow along the edge of the woods is probably the best route, but you lose security. Keep in low places in the ground. In any event, your mission, ease of movement, shadow mist, and background are controlling factors.
The difference between night and day movement is further highlight by the following figure:
click for larger
Methods of approach for individuals and small groups.
Some General 'Guidelines'
Move with caution at all times. Expect danger and take necessary precautions (men ready to cover one another, slow movement, general prudence).
Pick your route ahead of time and carefully. Determine possible positions where the enemy may be waiting. Observe first!
Make use of all available cover, screens, or concealment. Anything is better than nothing.
Remember where you have been, where you need to go, and your mission.
If you get lost, do not panic, stop where you are and think carefully about your last steps. Recall the map in your mind (or pull it out). Carefully reorient yourself using features of the terrain.
"The scout should not return by the same route. His best guide to his return is his memory of the landmarks passed on the way out. He must cultivate the ability to recognize points he has seen once."