At 2038 your position is LAT 41°09.2'N, LONG 71°40.6'W. You are on course 301° per standard magnetic compass at 7.2 knots. At 2152 your position is LAT 41°11.3'N, LONG 71°48.6'W. What were the set and drift?
• Set and drift: set is the direction the current carries you (in °T), drift is the speed of that current (knots) • Difference between DR track (what you steered and speed through the water) and actual track over ground (positions plotted on chart) • Converting standard magnetic compass course to true course using variation and deviation (use your exam’s table/chart)
• First, plot both positions and connect them to find your actual course and distance made good over the ground between 2038 and 2152 • From your compass course and speed, construct the DR track for the same time interval; compare its endpoint to the second fix • Use the line from DR endpoint to the actual fix: its direction gives set, and its length over time gives drift
• Make sure you correctly convert standard compass course to true course before plotting the DR • Carefully calculate the time interval between 2038 and 2152 and use it consistently for both DR distance and drift calculation • Verify that your final set direction is given in true degrees and your drift is in knots, then compare both to the multiple-choice options
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