What is defined as the method of navigation that relies solely on a compass?

Dead reckoning is the method of navigation that relies solely on a compass, making it the correct answer. This technique involves calculating one's current position by predicting future positions based on a previously determined position, speed, duration, and direction of travel. The compass plays a crucial role in this calculation, as it provides the necessary heading information to navigate effectively.

In practice, dead reckoning can include other factors like wind speed and current in maritime contexts, but at its core, it fundamentally relies on the compass to establish a course. This method is particularly valuable in conditions where landmarks or celestial cues are not available for navigation.

The other choices involve different navigation methods. Wayfinding refers to the process of navigating based on environmental cues or patterns rather than relying solely on instruments. Celestial navigation uses celestial bodies such as stars and planets to determine one's position. GPS navigation, on the other hand, uses satellite signals to ascertain geographic location, which is entirely independent of compass usage.