🔍 Key Concepts

• Set is the direction toward which the current pushes your vessel, measured from the DR (dead-reckoned) position to the fix • Drift is the speed of the current, found from the distance between the DR position and the fix over the time interval • Use basic speed–distance–time: ( \text{Drift} = \frac{\text{Distance between DR and fix}}{\text{Time in hours}} )

💭 Think About

• First, plot or determine your DR position at 1950 using your course and speed from 1930 to 1950. Where would you be with no current? • Next, draw the vector from the DR position to the 1950 fix (37°12.3'N, 75°38.6'W). In what true direction does that vector point? • Measure the distance between the DR and fix, convert it to nautical miles, then divide by the 20‑minute interval (in hours) to find the current’s speed.

✅ Before You Answer

• Be sure you’re using the DR position at 1950, not the earlier position, when determining set and drift • Check that your set is expressed as the direction TOWARD the fix from the DR position (true bearing), not the opposite • Confirm your drift calculation: distance in NM ÷ (20/60 hr) and see which answer choice’s speed is closest to that value