Quick Answer
Reassess declination every 100 miles or after traveling through an area with significant changes in magnetic declination.
Every 100 Miles Matters
Reassessing declination every 100 miles is crucial for maintaining accurate navigation. This is because declination can change significantly over long distances, and failing to account for these changes can lead to large errors in navigation. For example, in some areas, the declination can change by as much as 10-20 degrees over a short distance.
Using A Declination Map
When traveling through an area with significant changes in magnetic declination, it’s essential to use a declination map to stay on track. These maps provide a detailed representation of the declination across different regions, allowing you to make adjustments to your navigation as needed. Typically, declination maps are available for purchase or can be downloaded from online resources.
Understanding Your Compass
It’s also crucial to understand how your compass works and how to adjust for declination. Most compasses have a declination adjustment feature, which allows you to account for the change in declination. To use this feature, you’ll need to set the declination to the current value for your location, and then adjust the compass accordingly. This can typically be done by rotating the bezel on the compass to match the current declination.
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