Compass and Orienteering Skills

Orienting a Map Using a Compass

Use the following step-by-step reminders when you want to orient a map or triangulate.

1. Lay the map on a level surface.

2. Located the declination diagram in the lower left corner of the map.

3. Lay the compass on top of the diagram.

4. Without disturbing the compass, rotate the map until the line that

points to magnetic north in the diagram on the map lines up with the

red needle of the compass.

Taking a Bearing from a Map (when map is not oriented)

Use this method when you know your exact position on the map and want to walk or paddle in a straight line to some distant point that you have located on the map. It is critical that your actual position be very close to your estimated map location. If you cannot pin-point your location on the map, try traveling to the nearest point that you can identify with absolute certainty, even if it means going somewhat out of your way.

1. Identify NESW on the map, then locate these directions on land.

Point to your location on the map and where you want to travel.

Ask yourself, "if I want to go from here to there, in which direction

would I travel?" This is our estimate of what bearing you will need

to follow in order to reach the destination.

2. Put the compass edge along the intended line of travel, with the

direction of travel arrow pointing in the direction you want to go.

3. Now calculate your bearing by turning the compass housing until

the meridian lines inside the housing are parallel to the meridian grid

lines on your map (or, the side of the map if your map doesn't have

grid lines). The north orienting arrow on the compass housing ("the

Shed") must be pointing toward the top of your map.

4. Read the number on the housing dial at the base of the direction of

travel arrow; this is your bearing.

5. Compare your estimate with your calculation. Are they similar

(within 30-degrees of each other)? If so, proceed. If not, re-

calculate; have you reversed your bearing by 180-degrees.

Now that you have estimated and calculated your bearing, it's time to declinate using simple math and following the steps below.

To compensate for Declination in the Eastern US:

Add the number of degrees indicated on your map legend. In Maine, it is between 17-degrees and 20-degrees.

Rotate the compass housing to reflect this addition; this is your declinated bearing.

For example, if your calculated bearing was 137-degrees, your declinated bearing would be 157-degrees if you have a 20-degree declination calculated.

Finally, it's time to navigate. Stand up, holding the compass in front of your stomach with the direction of travel arrow pointing away from you. Turn your whole body until Red Fred is in the Shed (until the magnetic needle is housed inside the north orienting arrow on the compass

housing). Walk following the direction of travel arrow (not the red needle).

In summary to navigate using a compass you must

Estimate your bearing
Calculate your bearing using a compass
Declinate by adding X
Navigate by following your bearing

You can also use other navigating techniques such as triangulation, establishing a Line of Position (LOP), and triangulation with two or more KF's .

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