United States Coast Guard Captains License Practice Exam

The term "dead reckoning" in navigation specifically refers to a method of estimating a vessel's current position based on its last known position, along with the course and speed that it has traveled since that last known position. This technique is fundamental in navigation, especially when direct and reliable navigational aids are not available, and it allows mariners to keep track of their movement over time.

Using dead reckoning involves calculating the distance traveled in a particular direction and updating the vessel's position accordingly. However, it does not take into account external factors such as currents, winds, or other navigational influences, which can lead to errors in the estimated position. This method remains a crucial skill for mariners, especially when navigating in areas with limited visibility or when electronic systems fail.

The other options pertain to different aspects of navigation or vessel operation but do not define dead reckoning. Estimating time of arrival refers to calculating when a vessel will reach a particular point given its speed and distance, which is a separate concept. Tracking weather changes involves monitoring atmospheric conditions, an important part of navigation but not directly related to position estimation. Calculating fuel needs is concerned with efficiency and operational planning rather than directly determining the vessel's position.