Quick Answer
True North is important for navigation accuracy because a compass points to Magnetic North, which is not always the same as True North due to the Earth's magnetic field declination.
Understanding Magnetic Declination
Magnetic declination, also known as magnetic variation, is the difference between Magnetic North and True North. It varies by location and can change over time due to geological movements and the Earth’s magnetic field shifting. For example, in the United States, declination ranges from -20 to 20 degrees, with an average variation of around 10 degrees. To ensure accurate navigation, it’s essential to account for declination when using a compass.
Calculating Declination for Navigation
To calculate declination, you can use a declination chart, consult a navigation app, or use an online tool. This will provide you with the current declination for your location. When using a compass, you need to adjust the direction-of-travel arrow to account for the declination. For example, if the declination is 10 degrees east, you would adjust the compass 10 degrees east of the desired direction. If you’re navigating without a compass, you can use the sun, stars, or landmarks to find True North and then adjust for declination.
Accurate Navigation Techniques
To ensure accurate navigation, it’s essential to use a combination of techniques, including using a compass, map, and landmarks. When using a compass, make sure to account for declination, and consider using a baseplate compass with a built-in declination adjustment. You should also regularly check your compass and map for any updates or changes in declination. By following these techniques, you can increase your navigation accuracy and stay on course.
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