🔍 Key Concepts

• Compass deviation vs. variation and how each is determined • What it means when two charted objects that should be in line (range) are observed on a different compass bearing • How a deviation table is created and when it is considered verified or needs checking

💭 Think About

• If two fixed navigation aids are known to be exactly in line, what does it tell you about your compass reading when you observe them in line on a particular heading? • Does a single observation on one heading prove the entire deviation table is correct, or does it tell you something only about that specific heading? • Think about whether you can compute a numerical value for deviation from the information given, or only confirm/check something qualitatively.

✅ Before You Answer

• Check whether you are given enough data to calculate an exact deviation in degrees (including the sign E or W). • Consider if the information given proves anything about all headings or only about the one you are on when the range lines up. • Verify whether the question is asking you to compute a value or to decide what action or conclusion is justified with the limited information.