🔍 Key Concepts

• Azimuth of the Sun and how to get true bearing from sight reduction tables or a calculator • Converting chronometer time to zone time and then to Greenwich Hour Angle (GHA) and Local Hour Angle (LHA) • Relationship between true bearing, gyro bearing, and gyro error (East/West)

💭 Think About

• First, convert the chronometer time (with its error) to the correct UTC time at the instant of the sight. How does this relate to GHA of the Sun? • Using the DR position and the correct time, determine the true azimuth (true bearing) of the Sun at that moment. What is the approximate direction the Sun should be from your ship? • Compare the computed true azimuth with the observed gyro bearing. In what direction (east or west) must the gyro compass be in error to make the gyro reading match the true bearing?

✅ Before You Answer

• Be sure you apply the chronometer error with the correct sign (slow vs fast) before using the time • Confirm that the latitude is south and the longitude is west when determining LHA and selecting the correct sign in sight reduction or calculator inputs • When deciding E or W error, double-check: If gyro bearing is greater/less than true bearing, which way is the error named? Review the rule before picking an answer.