By Marcin Wojtyczka

3 minutes read

In this article in series about RYA certifications we reveal what is covered by the Yachtmaster Ocean Shorebased Theory course.

RYA Yachtmaster Ocean Shorebased Theory course is an advanced 5 days training that covers all aspects of ocean navigation with particular emphasis on the use of celestial (astro) navigation, worldwide meteorology, passage planning and long-distance communications at sea. The sessions on astro navigation will unlock the mysteries of the sextant and allow you to confidently take sights at sea to obtain your position and carry out compass checks. It assumes a knowledge of all subjects covered in the other shorebased courses.

The course is suited to those that aspire to bluewater cruising or who just want to learn traditional navigation.

Having successfully passed this theory course you will be ready to put the theory into practice on an ocean voyage. You will also be exempted from the written Yachtmaster Ocean examination.

Syllabus

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 the 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 Sight Reduction Tables for Air Navigation (Pub. No 249) and the basic sight form

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 errors: index, side, perpendicularity, collimation

4. Measurement of time

  • Definition of, and the relationship between, UT, LMT, standard time and zone time
  • Chronometers and watches

5. Meridian altitudes

  • Approximating time of meridian altitude
  • Reduction of meridian altitude sights

6. Sun, star and other sights

  • Reduction and plotting of sun sights using Nautical Almanac and Sight Reduction Tables for Air Navigation (Pub. No 249)
  • The plotting of sun-run-sun meridian altitude
  • Reduction and plotting of sights obtained from stars, moon and planets
  • Plotting of sights obtained from stars, moon and planets

7. Compass checking

  • Use of amplitude and azimuth tables systems
  • Compass dip error

8. Satellite Navigation Systems

  • Principles and limitations of the use of all systems

9. Great circle sailing

  • Comparison of rhumb lines, great circles
  • Vertices and composite tracks
  • The computation of a series of rhumb lines approximating a great circle by use of Gnomonic and Mercator projections
  • Weather routing (weather-determined routes)

10. Meteorology

  • General pressure distribution and prevailing winds over the oceans of the world
  • Surface current trend around the globe
  • Tropical weather and trade winds
  • Inter Tropical Convergence Zone (ITCZ) aka doldrums
  • Tropical Revolving Storms (TRS): conditions to start, seasonal occurrence and forecasting by observation, escape strategy
  • Buys Ballot’s law, the wind veering and backing

11. Passage planning

  • Publications available to assist with planning long passages (routeing charts, pilot books, ocean passages of the world and other publications)
  • Preparation for ocean passages including survival equipment, victualling, water and fuel management, chafe protection, spares and maintenance, emergency equipment
  • Passage planning as per SOLAS chapter V, Annex 25 of IMO Resolution A.893(21)

12. Passage making

  • Navigational routine
  • Watchkeeping
  • Crew management

13. Communications

  • Satellite and terrestrial systems
  • HF & SSB radio
  • Weather information
  • Distress
  • Internet sites

Accompanying course materials

  • Provided as part of the course