What should a DP operator do if there is a "heading difference error" between two selected Gyro Compasses?

When faced with a "heading difference error" between two selected Gyro Compasses, the correct course of action is to compare the two gyros with the Magnetic Compass before making any further decisions. This approach is vital because it enables the DP operator to ascertain which Gyro Compass provides the most accurate heading information based on a reliable reference point—the Magnetic Compass.

Gyro compasses can occasionally drift due to various factors, including the ship's movement or local magnetic interference. By comparing the readings from both gyros against the Magnetic Compass, the operator can determine if one of the gyros is indeed malfunctioning or if the error is within an acceptable range. This step ensures that the DP system is functioning with the best available heading reference, which is crucial for maintaining the vessel's position accurately.

Taking immediate action by changing the preferred Gyro without verification could lead to further inaccuracies, as the problem may not lie with the selected Gyro. Ignoring the alert is also unwise, as heading differences can indicate significant issues that could affect vessel safety and performance. Similarly, proceeding without checking the error could exacerbate any existing issues and compromise situational awareness. Thus, the recommended practice is to conduct a thorough comparison with the Magnetic Compass, which serves as a valuable