🔍 Key Concepts

• Compass error as the difference between true and indicated (gyro or standard) heading • The meaning of the abbreviation pgc and how it differs from psc • The sign convention: when the compass reading is east or west of the true direction, how you label the error (E or W)

💭 Think About

• First, identify what pgc stands for and which instrument’s error you are being asked for • Think about how, on this type of exam problem, you normally obtain the true course at that time (e.g., from a line of position, charted track, or a known bearing) and compare it with the 240°pgc • Decide whether the compass is reading too high or too low compared to true, and from that determine whether the error is east or west

✅ Before You Answer

• Be sure you know whether you’re dealing with a gyro compass or a magnetic/standard compass when you see pgc • Confirm you have the true course or true bearing at 0610 from the problem’s plot or prior steps before you try to compute error • Check your final sign: verify whether the compass is displaced east or west of true, not just the numerical difference in degrees