Celestial Navigation · Intercept Method
Your computed altitude (Hc) is 45°20.0' and your observed altitude (Ho) is 45°32.0'. What is the intercept and its direction?
- A52.0' toward the body
- B12.0' away from the body
- C12.0' toward the body✓ Correct
- D12.0' along the azimuth from the GP
Explanation
Intercept = Ho − Hc = 45°32.0' − 45°20.0' = 12.0'. The memory aid 'HoMoTo' — Ho More, Toward — means when Ho is greater than Hc the line of position lies 12.0' toward the body along the azimuth.
Authority: Bowditch (Pub. No. 9), Marcq St. Hilaire (intercept) method
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
- Intercept Method
In the altitude-intercept (Marcq St Hilaire) method, the intercept is the difference between the:
- Intercept Method
When the observed altitude (Ho) is greater than the computed altitude (Hc), the intercept is plotted:
- 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: