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 gyrocompass and the charted value of the range of lights is 359°T, what is the gyro compass error?
• Gyro error = True bearing − Gyro bearing (watch the sign) • The relationship between east/west error and whether gyro reads high or low compared to true • The fact that the vessel is lined up with a charted range (true bearing) while steering a gyro heading
• If the true bearing of the range is 359°T, but your gyro heading to stay on that line is 001°G, is the gyro reading more or less than true? • When the gyro reads higher than true, is the error labeled east or west? What about when it reads lower? • Compute the difference in degrees between 359° and 001°. Then decide: should that be called east or west error?
• Be sure you are comparing true vs. gyro in the same direction (don’t mix up which one is bigger). • Double-check whether gyro high = error east or gyro high = error west before picking your answer. • Confirm that the smallest angular difference between 359° and 001° is used (don’t accidentally use 358°).
No comments yet
Be the first to share your thoughts!