Your vessel is steering course 299°psc, variation for the area is 7°W, and deviation is 4°W. The wind is from the southwest, producing a 3° leeway. What true course are you making good?
• Compass error and how it relates to variation and deviation • Order of applying corrections when converting between per ship’s compass (psc) and true • Effect and sign of leeway (from which side the wind is blowing and which way it pushes the bow)
• Start from 299° per ship’s compass and think: do you first remove deviation, then variation, or the other way around when going to true? • Ask yourself: if both variation and deviation are west, does that make true higher or lower than compass? • With wind from the southwest, which direction does it tend to push a vessel that is generally heading northwest, and does leeway get added or subtracted from the course made good?
• Be clear whether you’re converting psc → compass → magnetic → true (or similar) and apply corrections step-by-step. • Check the sign convention: remember the standard memory aid for east/west corrections (e.g., "east is least, west is best" or its equivalent) and how it affects the numeric value. • Confirm whether leeway should be applied to the right or left of the heading, based on where the wind is coming FROM.
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