Why is dead reckoning an important skill for navigators?

Dead reckoning is a fundamental skill for navigators because it enables them to estimate their current position based on previously determined data, such as speed, course, and time traveled. This method involves plotting a course on a chart and using the last known position as a reference point, then applying factors like speed and heading to anticipate where the vessel will be after a given duration.

This approach is crucial, especially when other navigational aids are unavailable or when navigating in areas where celestial observations or landmarks are not visible. By continuously updating their estimated position using dead reckoning, navigators can maintain situational awareness and ensure they are on the correct course, thus mitigating the risks of becoming lost or drifting off course.

The other options do touch upon aspects of navigation, but they do not specifically highlight the core purpose of dead reckoning. For example, while determining fuel efficiency and estimating time of arrival are important navigational considerations, they are not directly tied to the process of calculating one's position from past movements, which is the essence of dead reckoning.