Your ship is entering port from sea, and you sight a pair of range lights. When in line, they bear 315° per standard magnetic compass. The chart shows that the range bearing is 312°T, and that variation is 6°W. What is the deviation of your compass at the time of the sighting?

Question

Accepted Answer

Option D: 3°E. Compass error is difference between magnetic and compass headings (Error = Magnetic - Compass). Magnetic equals True minus Variation (312°T - (-6°W) = 318°M). Deviation is Compass Error minus Variation; 315° PSC versus 318°M gives 3°E deviation.