How does magnetic declination affect navigation?

Magnetic declination is the angle between magnetic north (the direction your compass points) and true north (the direction you need to go). This angle can vary significantly depending on your location and even change over time. Because of this discrepancy, adjustments must be made to ensure accurate navigation.

When navigating, if a pilot does not take magnetic declination into account, they would be using a compass reading that could lead them off course. By adjusting for the magnetic declination, which can be either east or west depending on whether magnetic north is to the east or west of true north, a navigator can ensure that the heading used corresponds accurately to the desired track over the ground.

This makes it essential for navigators to be aware of the local magnetic declination and to apply the necessary corrections to their compass headings. Without this adjustment, navigators risk systematic errors that could result in significant deviations from their intended route.