Book today and pay your deposit of £150.00

Learn to navigate by the stars! 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. The course is suited to those who wish to go ocean cruising, it will equip you with the skills needed to carry out an ocean passage either as a skipper or mate.

This course is essential preparation for a qualifying passage for the RYA Yachtmaster Ocean Examination. Once you have completed your qualifying 600 mile (minimum) passage you can take the RYA Yachtmaster Ocean Certificate of Competence Oral exam, completion of this shorebased course exempts you from the Yachtmaster Ocean written exam.

Prior to the course your navigation skills should be at the standard of the Coastal Skipper and Yachtmaster Offshore shorebased course. The course is taught over 40 hours with one exam paper. 

What’s included?

You will be coached over the RYA Yachtmaster ocean theory syllabus by one of our experienced Ocean instructors in our waterside classroom.

  • Yachtmaster Ocean course materials
  • RYA Astronavigation book
  • Use of sextant
  • Tea and Coffee (Only courses at EASS)
  • Parking

Maximum teaching ratio - 12:1 

Course language - English

Consecutive days: A non-residential course available over five days commencing on Monday at 0930h and ending approximately at 1700 Friday

Over Two Weekends: A non- residential course available over 2 weekends

  • 3 day weekend: commencing on Saturday at 0930h and ending approximately at 1700 Monday
  • Miss a weekend
  • 2 day weekend: commencing on Saturday at 0930h and ending apprximately at 1700h Sunday


Online course - Work through the syllabus anywhere in the world online at your own pace with our distance learning option.

RYA Yachtmaster Ocean Theory Certificate. 

Local Accommodation – if you need accommodation for the theory part of the course we can recommend a self-contained studio flat ‘The Sail Loft’ which is available within walking distance from the Marina where our classrooms are based. Please check availability with us.

The earth and the celestial sphere

Definition of the 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

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

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.

Measurement of time

Definition of, and relationship between, UT, LMT standard time and zone time

Rating of chronometers and watches

Meridian altitudes

Forecasting time of meridian altitude

Reduction of meridian altitude sights

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

Compass checking

Use of amplitude and azimuth tables systems and/or calculator

Satellite Navigation Systems

Principles and limitations of use of all systems

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 gnomic and Mercator projections


General pressure distribution and prevailing winds over the oceans of the world

Tropical revolving storms, seasonal occurrence and forecasting by observation

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

Passage making

Navigational routine


Crew management


Satellite and terrestrial systems

Weather information

Course Availability

5 days

Date Availability Price Book
22nd November '21 Places Available £485.00 Book Now
--> --> --> -->