Quick Answer
Align compass bezel with mapped route between known points. Rotate compass housing until orienting lines align with map grid lines. Rotate housing 15° west in most areas compensating for magnetic declination. Rotating compass case aligns orienting arrow with red needle marking north. Hold level and walk toward direction bearing points.
Understanding Magnetic Declination
Magnetic north differs from true north varying by region. Eastern areas have westerly declination—magnetic north points slightly west of true north. Western areas have easterly declination. Declination angles appear on map margins. Failing to account for declination causes navigation errors—1° declination equals 92 feet off course per mile of travel.
Using Compass with Map
Place compass on map with edge connecting starting point to destination. Rotate compass housing until orienting lines align with map grid lines. This orients the compass to map bearing. Add or subtract declination as appropriate for your region. Rotate your body until red needle aligns with orienting arrow—direction of travel arrow points toward destination.
Field Navigation Technique
Hold compass level with direction of travel arrow pointed ahead. Rotate your entire body (not just arms) until magnetic needle aligns with orienting arrow. Travel in direction of travel arrow using distant landmarks as waypoints. Periodically re-check bearing especially after terrain obstacles.
Triangulation for Position Finding
Identify three or more known landmarks visible from your position. Take bearing to each landmark. Plot reverse bearing from landmarks toward your position on map. Intersection of lines indicates location. This technique determines position when unsure of current location.
Compass Maintenance
Keep compass away from magnetic interference—electronics, metal objects. Protect glass face from breaking. Liquid-filled compasses resist vibration better than sealed air-filled versions. Even inexpensive baseplate compasses provide adequate accuracy for wilderness navigation.
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