Your vessel is proceeding up a channel, and you see a pair of range lights that are in line dead ahead. The chart indicates that the direction of this pair of lights is 343°T, and the variation is 5° west. If the heading of your vessel at the time of the sighting is 344° per standard magnetic compass, what is the correct deviation?
Official USCG Answer & Rule Citation
Correct Answer: Option C — 4°E
The range provides a True heading of 343°T. With a magnetic heading of 344°M and variation of 5°W, the magnetic heading converts to 339°T (344°M - 5°W). The difference between the compass heading (344°M) and the magnetic heading (339°T + 5°W = 344°M) results in 4°E deviation.
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