When using a hand-held compass, why is it important to check for magnetic disturbances?

Checking for magnetic disturbances while using a hand-held compass is crucial because these disturbances can significantly affect the accuracy of the bearing the compass provides. Magnetic disturbances can arise from various sources, such as nearby metal objects, electronic devices, or even natural elements in the environment, all of which can cause the magnetic needle to deviate from true magnetic north.

When these disturbances occur, the readings taken from the compass may not reflect the actual direction, leading to navigational errors. It is particularly essential in critical situations, such as navigating in unfamiliar or challenging terrains, where precision is paramount for safety and effective course plotting. Therefore, being aware of possible magnetic influences and verifying the reliability of the compass reading helps ensure navigational accuracy, which is the primary reason for checking for such disturbances.