Your vessel is steering course 352°psc, variation for the area is 11°E, and deviation is 9°W. The wind is from the northeast, producing a 1° leeway. What true course are you making good?
• Relationship between compass course, deviation, magnetic course, variation, and true course (TVMDC) • How east and west variation/deviation affect the conversion steps • Effect of leeway: wind from a given direction pushes the vessel downwind (to leeward)
• Start from 352°psc and carefully step through TVMDC to convert to true, paying attention to signs for 11°E and 9°W. • Decide whether leeway should make your course made good slightly larger or smaller than the true course through the water, given that the wind is from the northeast. • Compare your computed result to the multiple‑choice options and see which is closest after applying both corrections and leeway.
• Be clear on whether west deviation is added to or subtracted from the compass course when finding magnetic course. • Confirm whether east variation is added to or subtracted from magnetic to find true course. • Think about the direction of sideways push: with wind from NE on a nearly northbound course, are you set to port or to starboard? This decides if you add or subtract the 1° leeway.
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