Your vessel is proceeding up a channel steering on a pair of range lights that are in line ahead. The chart indicates that the direction of this pair of lights is 249°T, and the variation is 14°E. If the heading of your vessel at the time of the sighting is 226° per standard magnetic compass, what is the correct deviation?

Correct Answer: Option A — 9°E

Compass error is derived from the algebraic difference between true course and magnetic heading, considering easterly variation as negative relative to true. Applying the standard conversion formula (True +/- Variation = Magnetic; Magnetic +/- Deviation = Compass) resolves the correct deviation.