Yachtmaster Ocean

Astro-navigation & ocean passage planning

"This is the best RYA theory course"
Practicing with a sextant

Perhaps GPS and chart plotters make us think it's not necessary to learn about celestial navigation these days. But aren't you fascinated to know how mariners of old navigated by the sun and the stars?

"John is a first class instructor who presents what at times seems daunting material in a clear & easy-to-follow way.  The online resources between Saturdays were excellent."  Dave

While there are a lot of calculations involved in astronavigation, you don't have to do them yourself!  It's more a matter of looking up the answers in tables.

If you can add or subtract minutes up to 60' & add or subtract up to 360°, you're good to go!

For example: Add 245° 51.7' to 120° 18'

The minutes total = 69.7' but that's more than 60 so it actually becomes 1° 9.7'

The degrees total = 365° + the extra 1° from the minutes, so that's 366°. This is 6° too many from the 360° available.

So the answer to the sum becomes 6° 9.7' and that's pretty much as hard as the maths gets! 

Yachtmaster Ocean Course Topics

Dolphins in the Celtic Sea
  • Learn about astronavigation & ocean meteorology
  • Become qualified to skipper a yacht in all parts of the world
  • Know how to navigate if your GPS fails
  • Be cool with a sextant!

The cost includes the RYA course pack and certificate.

"As always, the course was presented in very strong practical application terms.  Celestial navigation appeared daunting, but was presented in a very enjoyable and understandable manner."

Yachtmaster Ocean 5-Day Course Dates winter 2023 TBC Start Time Places Left
Contact us if you are interested in this course 9.00 am 12 

Course joining instructions

Plotter & Dividers

A plotter & dividers is essential.

Symbols and Abbreviations

You may find this book very useful.


You may find this book very useful.

6 Day Course

Duration: 40 hours plus homework and assessments
Student to instructor ratio 12:1