You are steering 318°psc. A northeasterly wind causes 3° of leeway. The variation is 14°E and the deviation table is extracted below. What will be the true course made good?
DEVIATION TABLE Magnetic Heading Deviation 300° 2°E 315° 0 330° 2°W
• Relationship between compass, magnetic, and true headings (CTD-V-M-C ladder or similar memory aid) • How to interpolate deviation between tabulated headings • Effect of a northeasterly wind on leeway direction (does it push your track to the left or right of your heading?)
• Start from 318° per standard compass and work step-by-step to find the corresponding magnetic heading using the deviation table. • From your magnetic heading, apply the 14°E variation correctly to find the true heading before considering leeway. • Decide whether the 3° leeway should be added or subtracted based on the fact that the wind is from the northeast; think about which way the vessel is being pushed off course.
• Be sure whether east deviation and variation are added or subtracted when converting from compass to true. • Check that your interpolated deviation at 318° falls logically between the listed values at 315° and 330°. • After applying leeway, confirm whether the course made good should be a larger or smaller number than the ship’s true heading, given a wind from the northeast.
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