Your vessel is proceeding up a channel, and you see a pair of range lights that are in line ahead. The chart indicates that the direction of this pair of lights is 064°T, and the variation is 17°W. If the heading of your vessel at the time of the sighting is 094° per standard magnetic compass, what is the correct deviation?

Question

Accepted Answer

Option B: 13°W. True range of 064°T with a variation of 17°W gives a magnetic bearing of 081°M. Comparing this with the standard magnetic compass heading of 094°psc determines a deviation of 13°W based on standard deviation calculation procedures.