You swung ship and compared the magnetic compass against the gyro compass to find deviation. Gyro error is 2°E. The variation is 8°W. Find the deviation on a true heading of 187°.

Correct Answer: Option C — 0.5°W

Apply the standard compass relationship formula: True = Magnetic + Variation, and True = Gyro ± Error. Using the gyro heading and 2°E gyro error to establish true heading, then combining true heading with 8°W variation yields the magnetic heading, directly revealing the 0.5°W deviation.