Chart Navigation & Plotting · Compass — Gyro Error by Range
A charted range bears 045°T. As you cross it, the gyrocompass reads 047°. The gyro error is:
- A2°E
- B2°W (gyro reads high; subtract 2° from gyro bearings)✓ Correct
- C2°W (add 2° to gyro bearings)
- D0°
Explanation
The true bearing of the range is 045°; the gyro shows 047°, reading 2° high. 'Gyro best (higher), error west.' The error is 2°W, and 2° is subtracted from gyro bearings to obtain true.
Authority: Bowditch (Pub. No. 9), Gyro Error
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