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    Estimated to be about 30 hours of your time, depending on how much optional material you wish to cover. You work at your own pace on your own schedule. See extended discussion of this in the Frequently Asked Questions.


    You can start at any time, and submit quizzes and discussion any time of day or night. The lesson quizzes must be submitted sequentially. You have one year to complete the course, or request an extension if needed.

Course description

    This course covers all aspects of practical celestial navigation, starting from the very basics and ending with all you need to safely and efficiently navigate an open ocean passage. This online version is a combination of our Home Study Course and our Classroom Course. To read more about these, please see the Frequently Asked Questions about the celestial course.

    This course is also an ideal refresher for those who have been away from the topic for some time, or just want more practice and perhaps see other approaches. For those with this experience already, you might just go straight to the quizzes and then fill in the training as required. Questions and comments from more experienced navigators would be a welcome and beneficial addition to the discussion groups.

    Most people doing the course intend to use the knowledge for actual navigation at sea, but we do often have people learning cel nav without that specific goal. It is a fascinating subject in its own right. Amateur astronomers, school teachers, kayakers, and others just interested in the sky and this subject have taken part. It is a very rewarding exercise.


How the course works

    Please read the general description of How the Courses work. Those notes apply to all courses. You can sign up for a course anytime.

    The celestial course builds progressively on previous lessons. An experienced navigator could jump to special topics by just submitting the earlier quizzes, but those new to the subject should study the material sequentially and post questions as needed. If you have questions about the course structure itself that are not answered here, please send an email to starpath.


    There are no formal prerequisites for the Celestial Course. We do basic plotting using parallel rulers and dividers, but that is also explained in the course. There are no math requirements other than addition and subtraction of angles and time, and we review that in detail in Lesson 1. You do not need a sextant to do the course, as explained in the FAQ. In many respects, celestial navigation is "easier" than coastal navigation, but the knowledge is accumulative. It is valuable to work as many as possible of the practice problems in each lesson.

Student Objectives

  • Find position at sea from timed sextant sights of any celestial body
  • Carry out a running fix from the sun
  • Evaluate the accuracy of a celestial fix
  • Incorporate celestial fixes with DR plotting to navigate an ocean crossing
  • Understand the principles enough to apply them to basic emergency navigation
  • Identify any celestial body in the sky based on its approximate height and bearing
  • Know how to check the compass with sun or stars at sea without landmarks
  • ...please review the Lessons tab to see other topics covered.


    This course will prepare you for the certification tests offered from most organizations. Please see our Notes on Certification.