Celestial Navigation · Amplitudes — Compass Error
A body's computed true amplitude gives a rising bearing of 064°T. You observe it rise on a compass bearing of 060°. What is the compass error?
- A4°W
- B4°E✓ Correct
- C8°E
- D0°
Explanation
Compass error = true bearing − compass bearing = 064° − 060° = 4°. Because true is greater (to the right of) compass, the error is easterly: 4°E. The amplitude method gives a quick check of compass error at sunrise or sunset.
Authority: Bowditch (Pub. No. 9), Compass Error by Amplitude
Practice the full Celestial Navigation bank
Free spaced-repetition quizzing across 2190 USCG exam questions — it schedules your reviews so the ones you miss come back until they stick.
Related Celestial Navigation questions
- Amplitudes — Compass Error
You observe the sun's amplitude at sunrise as 074° per gyrocompass; the computed true bearing is 068.5°T. What is the gyro error?
- Time
The Nautical Almanac tabulates the positions of celestial bodies against which time standard?
- Time
A vessel in west longitude has a zone description of +5. To convert zone time to UT you must:
- Coordinates
How is the GHA of a star obtained from the Nautical Almanac?
- Coordinates
Sidereal Hour Angle (SHA) is best defined as:
- Coordinates
Declination of a celestial body is the celestial equivalent of: