Yachtmaster Ocean Theory Syllabus

This is a course in astro-navigation and worldwide meteorology which also reveals the mysteries of the sextant. It assumes a knowledge of all subjects covered in the other shorebased courses. 

1. The earth and the celestial sphere 

  • Definition of observer’s zenith and position of a heavenly body in terms of latitude, longitude, GHA and declination 
  • Right angle relationships, latitude and co-lat, declination and polar distance 
  • Relationship between GHA, longitude and LHA 
  • Tabulation of declination in nautical almanac 
  • Rate of increase of hour angle with time 

2. The PZX triangle 

  • The tabulated components of the triangle, LHA, co-lat and polar distance 
  • The calculable components, zenith distance and azimuth 
  • Relationship between zenith distance and altitude 
  • Introduction to the tabular method of solution in the Air Navigation Tables and the basic sight form 
  • The use of calculators for the solution of the PZX triangle 

3. The sextant 

  • Practical guide to the use and care of a sextant at sea 
  • Conversion of sextant altitude to true altitude 
  • Application of dip, index error and refraction 
  • Correction of side error, perpendicularity, index error and collimation error 

4. Measurement of time 

  • Definition of, and relationship between, UT, LMT, standard time and zone time 
  • Rating of chronometers and watches 

5. Meridian altitudes 

  • Forecasting time of meridian altitude 
  • Reduction of meridian altitude sights 

6. Sun, star and other sights 

  • Reduction and plotting of sun sights using 
  • Air Navigation Tables 
  • Awareness of use of calculator for sight reduction 
  • The plotting of sun-run-sun meridian altitude 
  • Awareness of the reduction and plotting of sights obtained from stars, moon and planets 

7. Compass checking 

  • Use of amplitude and azimuth tables systems and/or calculator 

8. Satellite Navigation Systems 

  • Principles and limitations of use of all systems 

9. Great circle sailing 

  • Comparison of rhumb lines and great circles 
  • Vertices and composite tracks 
  • The computation of a series of rhumb lines approximating to a great circle by use of gnomonic and Mercator projections 

10. Meteorology 

  • General pressure distribution and prevailing winds over the oceans of the world 
  • Tropical revolving storms, seasonal occurrence and forecasting by observation 

11. Passage planning 

  • Publications available to assist with planning of long passages (routeing charts, ocean passages of the world and other publications) 
  • Preparation for ocean passage including survival equipment, victualling, water and fuel management, chafe protection, spares and maintenance 

12. Passage making 

  • Navigational routine 
  • Watchkeeping 
  • Crew management 

13. Communications 

  • Satellite and terrestrial systems 
  • Weather information
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