Hold the compass steady directly in front of you. Keep it flat so that the needle points to north.
Turn the compass cover until the needle lines up with the orienting arrow (which is usually red). The zero degree mark should now be pointing to magnetic north.
Without changing anything else, turn direction of travel arrow until it points in the direction you want to move by twisting the base plate.
Read the number of degrees where the direction of travel arrow touches the compass numbers. Write down the number of degrees you read from the compass.
Place your map on a flat space and put the compass on it. Use the compass to orient the map toward magnetic north. Use the information you already have about the direction you want to go in concert with the surface conditions you see on the map. For example, you may see a peak in the distance you want to make for, but the map reveals that a direct line to this peak would be hazardous. In this case, you can plot a course avoiding the hazards and still make the peak.
