On 27 June your vessel's 0816 ZT DR position is LAT 22°14'S, LONG 53°52'W, when an azimuth of the Sun is observed. The chronometer time of the sight is 12h 15m 02s, and the Sun is bearing 047.5° per standard magnetic compass. The chronometer error is 00m 46s slow, and the variation in the area is 6.0°E. What is the deviation of the standard magnetic compass?

Question

On 27 June your vessel's 0816 ZT DR position is LAT 22&deg;14'S, LONG 53&deg;52'W, when an azimuth of the Sun is observed. The chronometer time of the sight is 12h 15m 02s, and the Sun is bearing 047.5&deg; per standard magnetic compass. The chronometer error is 00m 46s slow, and the variation in the area is 6.0&deg;E. What is the deviation of the standard magnetic compass?

Accepted Answer

Option C: 3.0&deg;W. Calculate the Sun's azimuth using the time of sight and DR position. Compare the calculated true azimuth to the observed compass bearing (047.5 degrees) to find the compass error. Applying the 6.0 degrees East variation to the total compass error results in a deviation of 3.0 degrees West.