🔍 Key Concepts

• Set and drift: Set is the direction the current pushes you toward; drift is the speed of that current. • Difference between dead reckoning (DR) position and observed fix from bearings to lights. • Using at least three LOPs (lines of position) from bearings to plot a fix and compare positions at different times.

💭 Think About

• How would you plot your DR position at 0130 using your course and speed, and then obtain your 0200 fix from the three bearings given? • Once you have both the DR and the 0200 fix, what does the line between those two points represent, and how can you turn that into a direction in degrees and a speed in knots? • Compare the distance between the DR and fix with the 30‑minute time interval: what drift (speed of current) does that distance correspond to?

✅ Before You Answer

• Be sure the bearings are plotted as true bearings from each aid to navigation, converting properly to lines of position through your vessel. • Confirm you correctly identify the DR position at 0200 (where you would be with no current) and the actual fix at 0200 (where the bearings place you). • Carefully check the direction of the line from DR to fix (set is the direction toward the fix from the DR) and compute the speed over 30 minutes to get drift in knots.