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Adjustable Declination Compasses

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A compass with adjustable declination allows you to rotate the orienting arrow independently of the compass dial. If you have such a compass, you may calculate your map bearing without adding or subtracting the amount of local magnetic declination. To calibrate your compass in this fashion, rotate the inner liquid capsule (or turn the screw with the key) until the orienting arrow deviates from the compass ring’s north indicator by the amount & direction of the local magnetic declination. For example, if local declination is 10 degrees east of true north, rotate the inner liquid capsule (or turn the screw with the key) until the orienting arrow points to 10 degrees east. If using Method #1, you do not need to add or subtract as indicated in step E; just make sure compass ring north (not the orienting arrow) agrees with map north as directed in step D. If using Method #2, skip steps G and H; again, be sure compass ring north (not the orienting arrow) agrees with map north as directed in step E.