What does "dead reckoning" rely on for navigation?

Dead reckoning is a navigation technique that primarily relies on knowing your current position and then calculating your future position based on speed, time, and direction. For this method to be effective, accurate direction is crucial, which is where a compass comes into play. The compass provides the navigator with the necessary direction to follow to determine the path taken across the terrain or sea.

While GPS coordinates, chart readings, and visual landmarks can certainly aid in navigation, they are not integral to dead reckoning itself. GPS relies on satellite signals for precise location data, chart readings depend on pre-existing navigational aids and data from nautical charts, and visual landmarks require external references that can vary and may not always be present. Therefore, a compass is fundamental to successfully executing dead reckoning as it allows the navigator to maintain a consistent bearing while calculating distance traveled over time.