What does "dead reckoning" navigation involve?

Dead reckoning navigation involves estimating your position by calculating the speed at which you are traveling and the distance you have covered over a certain period. This method is based on the principles of vector addition, taking into account the direction of travel, the distance moved, and the time elapsed since the last known position.

Dead reckoning is particularly useful when visibility is low or when navigational aids are not available, as it allows a mariner to maintain a course based on their last known location. While it can be somewhat less accurate over time due to factors like wind and current affecting the vessel's actual path, it remains a critical skill for navigating in various conditions.

Other methods mentioned in the choices, such as calculating time based on tide charts or using GPS, are distinct navigation techniques. Tide charts help inform navigators about water levels but do not directly relate to determining position. GPS provides precise location data, which differs significantly from the estimations made in dead reckoning. Following visual landmarks employs a completely different navigational approach, relying on identifiable geographic features rather than mathematical estimations based on speed and distance.