You are steering 154° per gyrocompass. The wind is northeast by east, causing 4° leeway. The gyro error is 3° east, variation is 11° west, and deviation is 7°E. What is the true course made good?
• How to apply leeway to a steered course (does leeway push you toward or away from the wind?) • The full sequence to convert from gyro course to true course accounting for gyro error, variation, and deviation • Remembering the sign convention: east is least, west is best when applying variation and deviation
• First, decide whether the leeway will make your course over ground larger or smaller than 154° based on the wind’s direction. • Then, adjust your gyro course for the known gyro error to find the equivalent magnetic/compass heading before applying variation and deviation. • Work step-by-step: gyro → (corrected for gyro error) → compass → magnetic → true, checking the sign (+/–) at each stage rather than doing it all at once.
• Be clear about the direction of leeway: is your actual track pushed to the right or to the left of your heading with a wind from NE by E? • Confirm whether a 3°E gyro error means the gyro reads too high or too low, and therefore whether you add or subtract it to get the real heading. • Carefully apply 11°W variation and 7°E deviation with the correct signs; double-check with the memory aid “east is least, west is best” before choosing your final true course.
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