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celestial navigation course

Celestial navigation course The UK's #1 course - taught by the experts


Come and join the number 1 rated celestial navigation course in the UK and learn to navigate at sea, using just the Sun, Moon, stars and planets. Taught by the experts at Rubicon 3 Adventure Sailing, this is two days of plain English, minimal jargon and top class tuition. You do not need any prior knowledge of celestial navigation to attend this course.

During the course, you will learn how to measure the altitude of the Sun and stars above the horizon and how to use that knowledge to fix your position, using the nautical almanac and sight reduction tables. You will also learn how to predict the time of meridian passage and calculate our latitude without using time, just as mariners did for centuries.


celestial navigation students


Aiming for RYA Yachtmaster Ocean?

Many people attend this course just to learn the skills. However, if you are wanting to take your RYA Ocean exam, this two day course will give you everything you need to be able to take your celestial sights at sea and fix your position. For further details on what is required to take Yachtmaster Ocean, read our briefing notes here.


Using sextant at sea

The course in detail

We start with a 15 minute “This is how celestial navigation works”. It really can be described that quickly. We then spend the first day working through the theory of celestial navigation. Where most other courses just teach you to fill in a form, we will show you what’s happening and why, giving you much deeper and more profound understanding. Indeed, without this deeper understanding, we argue you cannot safely use celestial navigation as you cannot sense check your work.

On day two, we look at the sextant and how to tune it and use it. We only cover this briefly as what will stop you using celestial navigation is not using a sextant (which is easy) but the calculations that come after it (called the sight reductions). You finish the weekend with a full plot of your position from celestial data, the Rubicon 3 celestial workbook and a number of ‘how to’ sheets to help you develop even further in the future.

What you need prior to attending the course

No previous knowledge of celestial navigation is required. You should have basic navigation and chart work – to approximately RYA Day skipper level. You do not need a sextant or any books – we provide everything you need.


celestial course components


What you’ll study

Using celestial bodies to fix position

  • Determine the time of visible rising and setting of the sun
  • Use standard methods to calculate altitude and azimuth
  • Use the nautical almanac and sight reduction tables to find a position line from an altitude obtained by a sextant
  • Accurately plot lines of position

Determining latitude by celestial means

  • Calculate your latitude by the meridian altitude of the sun
  • Calculate your latitude by Polaris
  • Calculate the time of meridian altitude of the sun or planet.

Determining compass error by celestial means

  • Determine compass error by amplitude of the sun or a planet
  • Determine compass error by azimuth or the sun
  • Determine compass error by azimuth of a star or planet

Looking to develop your celestial navigation at sea?

Once you’ve learnt the essential skills, come and head out to sea with us and navigate using your sextant. We run numerous passages through the year where we cover up the GPS and just use celestial navigation. Have a look at our spectacular Celestial Navigation Atlantic Ocean crossing, and our Celestial Navigation only route from NW Spain to the Canaries. You can also use the sextant on any of our other offshore and ocean passages, the majority of which can also be used as an RYA Ocean Yachtmaster qualifying passage.

Key Points

  • No previous celestial knowledge or equipment required
  • Classroom based
  • Teaches you the full celestial process
  • Courses run in London and Portsmouth. See drop-down for dates & locations

What's Included

  • All course materials including course notes and equipment.
  • Morning and afternoon tea.

What's not Included

  • Overnight accommodation
  • Lunch
  • FAQ

The course is taught in various parts of the country. When you select different dates from the drop-down you will see the location.


Unit 27, Victoria Quay, The Cooperage, Weevil Lane, Gosport, PO12 1AX. (Free parking available at this location)

All teaching is in a classroom, led by an expert Rubicon 3 instructor. Class sizes are limited to 8 students, to ensure that you have proper levels of interaction with the instructor. Students come with all different levels of prior knowledge, but do not worry. The entire syllabus is taught from the beginning, and no knowledge of the syllabus is expected prior to starting

The simple truth is that shore based courses in the sailing industry are often taught by people who have done very little sailing outside of their local area. This hugely limits their skills and experience, beyond repeating the same anecdotes and lines lesson after lesson.

At Rubicon 3, we sail year round to some of the world’s most remote and challenging regions. We are constantly learning, evolving and improving our approach to sailing and navigation. When you learn with us, you will be getting expert instructors teaching the latest approaches to the theory.

If you have been listening for longer than 10 minutes, then it’s time to stop. Any longer than that and whatever is coming out of the instructor’s mouth isn’t going to be having much impact. You will increasingly switch off because it is simply too much new information. It needs to be processed, before more information can be digested.

“To keep students engaged, you must win the battle for their attention every 10 minutes”.

The idea of teaching in 10 minute segments is well recognised as the approach that works. It is variously known as‘Chunk and Chew’, ‘Turn and Talk’, ‘Stop and Jot’ and  ‘Listen-Stop-and-Write’.

It works like this:

  • The instructor breaks all the content down into manageable portions and then allows time for learners to digest the information.
  • Students receive 10 minutes of rich teaching and content (listening, watching, reading)
  • They are then given 2 minutes to digest & discuss the content with a fellow student or to write notes individually.

It is well recognised now that when information is delivered in chunks, we remember more and the 2 minutes given for chewing is vital for absorbing, processing, discussing and comprehending. The research shows that the key to mastery of new concepts is frequent and persistent review of material.

The two minute breathers ensure the brain has a break and can consciously and subconsciously replay the content. Taking a breather also allows students to generate questions.

What time does my course start and finish?

Start: 0900hrs on Monday

Finish: 1600hrs on Friday

Do I need to book overnight accommodation?

Yes, unless you live nearby. These are not residential courses.

Is everything else I need included?

Yes. Your course comes with all the course notes you will need. You do not need to bring any other equipment. It is all provided.

Learn the end to end process of astro navigation

  • Introduction
  • Essential mathematics (not hard!)
  • Celestial navigation explained in 15 minutes
  • Hour Angle explained
  • Greenwich Hour Angle (GHA)
  • Local Hour Angle (LHA)
  • Circle of Equal Altitude
  • Nautical Almanac
  • Sight Reduction Tables
  • Using a sextant
  • Tuning
  • Measuring altitude
  • Plotting
  • Planets, stars, other celestial bodies


Course Fee



2 Days (Saturday & Sunday)

Previous experience required

Basic coastal navigation skills.

Course overview

2 days of expert tuition from Europe’s leading adventure sailing school


Various. See drop down.

Who we are

Blueco Holdings Ltd, t/a Rubicon 3 Adventure
20 – 22 Wenlock Road, London, N1 7GU

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