🔍 Key Concepts

• Difference between relative bearing and true/gyro/compass bearing • How to convert from pgc (per gyro compass) bearings to a relative bearing using own ship’s heading • Understanding that relative bearings are measured from the bow, clockwise 0°–360°

💭 Think About

• Start by writing down your own ship’s heading and the probable true/gyro bearing to Thimble Shoal Light based on the geometry of the fixes given. • Think about how you would normally compute a relative bearing if you know your heading and the target’s bearing: which angle minus which? • Ask yourself: after conversion, should Thimble Shoal Light appear ahead, on the beam, or abaft the beam based on your track and the given bearings?

✅ Before You Answer

• Make sure you are using 2215 bearings consistently and that all are in pgc (per gyro compass) before doing any subtraction. • Confirm you are measuring the relative bearing clockwise from the bow (0° at dead ahead), not from north. • Check whether your final relative bearing is between 0° and 360° and makes sense with your course of 271°pgc and the charted positions of the lights.