Which of the following is NOT one of the rules of dead reckoning (DR)?

Dead reckoning (DR) is a key navigational method that allows for continuous tracking of a vessel’s position by using its last known position, speed, course, and time traveled. The rules associated with dead reckoning ensure that navigators maintain an accurate and updated estimate of their current position.

The rule stating that a DR should be plotted at every chart update is not necessary within the context of dead reckoning itself. A chart update refers to changes or modifications made to the chart based on new information, but it does not dictate when a DR should be calculated or recorded. The essential actions of dead reckoning focus on changes in course, speed, or after obtaining a navigational fix.

By plotting a DR at each course change, a navigator takes into account the new direction the vessel is heading. Similarly, recording a DR at each speed change is crucial, as speed influences the distance traveled over time, affecting the estimated position. Additionally, plotting and labeling a new course after obtaining a fix ensures that any adjustments based on accurate position information are incorporated into the navigation plan.

Thus, while DR is vital for continuous position tracking, regular plotting after chart updates is not an inherent rule of this method.