On 9 September your 2043 ZT position is LAT 24°18'N, LONG 66°46'W. You observe Polaris bearing 001°pgc. At the time of the observation the helmsman noted that he was heading 031°pgc and 040°psc. The variation is 11°W. What is the deviation for that heading?

Correct Answer: Option B — 2°E

Determining deviation involves finding compass error by comparing gyro or true bearings to standard compass headings. Applying variation and gyro error to the observed bearings isolates the residual magnetic deviation for the specific ship's head.