Course details

Celestial Navigation

This course is designed to teach you all of the old (celestial - using only the celestial objects, sun, moon, stars and planets) navigation tricks used by the sailing masters prior to the age of electronic navigation.

This is open ocean navigation, not within the sight of land.

This class is only taught via self study, you can take ASA117 (Celestial Endorsement) live with us every year.


Although there are no prerequisites for this course, many of the skills covered in the Coastal Navigation are used here, so it is very wise to have completed a Coastal Navigation course.

Upon Completion:

You will have been taught all of the most common techniques used for hundreds of years to navigate across the world's oceans. The assumptions of the course are that the engine died long enough ago that there is no longer any electricity available - therefore no GPS or any other form of electronic navigation. ASA107 certification is available if you take the exam at the end of the course.

Exams can be taken in person at our office in Denver. If you are taking this course outside of the Denver area, exams can be taken via proctor!

Starting Dates:

Live Online Webinars:  This class is taught by an instructor, online, typically starting at the end of January each year on Tuesday evenings, running from 7:00 p.m. to 10:00 p.m. MST.  For the 2024 year, the starting date is Tuesday, January 23rd, 2024.  Recorded sessions are available at any time. The live sessions go for 3 weeks.

Recorded Sessions:  Since all of the sessions are recorded it is possible to start at any time and run through the recorded webinars at your own pace.  For 2 years from the date of purchase, you will be considered an "Active" student and will have access to all of the videos to complete the class.  You can reset the clock and retake the course for the cost of the materials package. 


  • Notes and Power Point presentation slides.
  • Relevant copies of the following publications - Nautical Almanac (daily pages, increments and S-tables), H.O. 249 (Volume I - Selected Stars and Volume II Lat 000 to 039).
  • H.O. 249 forms.
  • Universal Plotting Sheets.
  • Questions relating to the Lectures and Notes.
  • Answers to course questions.


  • Rolling Ruler (or Parallel Rules).
  • Dividers.
  • Several pencils and a VERY large eraser.
  • You WILL NOT need a sextant unless you wish to practice at home.

General Description:

Celestial Navigation uses the Sun, Planets, Moon and Stars to determine your Latitude and Longitude.

Topics covered are:

  1. Explanation of time zones and how to convert standard and zone time to GMT.
  2. How a sextant measures the arc from body to horizon.
  3. Index error, dip and altitude correction for Sun, Moon, Stars and Planet.
  4. Calculate time of meridian passage of the Sun for any given Longitude.
  5. Calculation of times of Sunrise, Sunset, and Twilight.
  6. Observers Latitude by Sun noon or twilight Polaris sights.
  7. Construction of a chart from a blank sheet of paper.
  8. Construction of a Universal Plotting Sheet.
  9. Solving the Celestial triangle using H.O. 249 tables.
  10. Solving the Celestial triangle using S-tables (included in the Nautical Almanac so you do not need the H.O. 249 tables).
  11. Determining Latitude and Longitude using any of the following celestial bodies - sun, moon, planets and 53 navigational stars.
  12. Plotting of Celestial L.O.P. on a Universal Plotting Sheet using simultaneous sights or running sight methods.
  13. Determination of Azimuths and Altitude of navigational bodies at twilight.
  14. Calculation of Compass Deviation using Celestial bodies.
  15. Computing Great Circle routes.
  16. Setting up and using an artificial horizon.


Dates include the classroom session. You can start the online portion instantly after purchase.