Celestial Navigation · Sextant — Non-Adjustable Errors
Which sextant error cannot be removed by the user's adjusting screws and must instead be measured and applied as a correction?
- AIndex error
- BInstrument (graduation/prismatic) error, listed on the sextant's certificate✓ Correct
- CPerpendicularity error
- DSide error
Explanation
Index, perpendicularity, and side errors are adjustable. Instrument error (errors in the arc graduation or optics) is non-adjustable; it is determined by the manufacturer, recorded on a certificate, and applied as a correction to observed altitudes.
Authority: Bowditch (Pub. No. 9), sextant errors
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
- 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:
- The Nautical Almanac
Approximately how fast does the GHA of the Sun increase with time?