What does the term speed made good refer to?

The term "speed made good" refers to the average speed of the vessel over a specific interval, taking into account the distance traveled and the time it took to cover that distance. This concept is crucial in navigation as it provides a more accurate measurement of a vessel's effectiveness in moving from one point to another, especially when considering factors like currents, wind, or course deviations that may affect the actual speed over the ground.

By calculating speed made good, navigators can assess their performance and make informed decisions regarding course adjustments or estimated arrival times. This differs from the maximum speed a vessel can achieve or the instantaneous speed at which the vessel might be traveling at any moment, both of which do not factor in the overall journey. Rather, speed made good is a practical metric for evaluating the actual progress of the voyage under various maritime conditions.