Yachmaster Ocean

The RYA Yachmaster Ocean Theory course is a voyage through astro navigation, worldwide meteorology and passage planning.

Required experience: Navigation to Coastal Skipper & Yachtmaster Offshore Shorebased standard.
Minimum duration: 40 hours plus exam time.
Minimum age: None.
Content: The earth and the celestial sphere; Practical guide to use and care of sextant at sea; Meridian altitudes; Sun, star and other sights, ocean passage planning.
Format: This is a shorebased course to be taken in the classroom. Students needing to take a sight at sea can book this separately.
Included in the fee: Educational material.
Not included in the fee: Accommodation & food, sight at sea.

This course and is ideally suited to qualified Offshore Yachtmaster who wish to progress to Ocean Yachtmaster.

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.
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
Forecasting time of meridian altitude.
Reduction of meridian altitude sights.

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 a 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.
Watch keeping.
Crew Management.

13. Communications
Satellite and terrestrial systems.
Weather information.