What determines the frequency of set and drift calculations?

The frequency of set and drift calculations is determined to be every fix because these calculations rely on the most accurate and current position of the vessel to provide an updated assessment of its course and speed over the ground. Calculating set and drift with each new fix helps in understanding the influence of tidal currents, wind, and other navigational factors on the vessel's actual path through the water.

By conducting these calculations every time a new fix is obtained, the Deck Watch Officer can make real-time navigational adjustments. This approach ensures that decisions are based on the latest navigational data, enhancing safety and effectiveness during operations. Other intervals, like every 5 minutes or every other fix, could potentially lead to outdated or less accurate assessments, impacting navigation quality and safety, particularly in dynamic environments. Thus, using every fix as the basis for these calculations is essential for maintaining situational awareness and operational integrity.