While your vessel is proceeding down a channel you notice a range of lights in line with your vessel's mast. If your vessel is on course 001° per gyro compass and the charted value of the range of lights is 359°T, what is the gyro compass error?

Correct Answer: Option D — 2°W

Gyro error is determined by comparing the observed gyro heading of a known charted range with its true value (Error = True - Gyro). Here, 359°T minus 001°pgc results in a gyro compass error of 2°W in accordance with standard piloting principles.