How often should a Dead Reckoning (DR) be calculated?

Calculating Dead Reckoning (DR) every hour on the hour is a standard practice in navigation because it allows for the most consistent and accurate tracking of the vessel’s position over time. Frequent calculations help account for any changes in course or speed, thereby providing a reliable means of estimating the current location based on prior data.

This hourly update is essential, especially in dynamic environments where navigational conditions can change quickly due to factors such as current, wind, or unexpected obstacles. Regular updates ensure that the watch officer maintains situational awareness and can make informed decisions regarding navigation and safety.

While other options suggest different intervals, they may not provide the same level of accuracy and responsiveness required for effective navigational practice on a vessel. With maritime operations involving various challenges, including navigational hazards and varying visibility, a consistent hourly calculation aids in maintaining the integrity of the vessel's course over time.