Celestial Navigation Standard (107)
General Description: Able to demonstrate the Celestial
Navigation theory required to safely navigate a sailboat on an offshore
passage. The practical application is conducted in the Offshore
A Certified Sailor has successfully demonstrated his or her ability to:
- Convert longitude into time.
- Convert standard time and zone time to GMT and vice versa.
- Calculate the zone time given longitude.
- Calculate the chronometer (or watch) error given a previous error and the daily rate.
- Apply the corrections for index error, dip of the horizon, and
total correction to convert sextant altitudes of the sun, stars,
planets, and moon to true altitudes.
- Calculate the time of meridian passage of the sun and
calculate the boat's latitude from the observed meridian altitude of
- Determine the latitude at twilight by means of the Pole Star.
- Solve the navigational triangle using a navigation table and show all appropriate work.,
- Plot celestial lines of position on a Mercator projection or on a universal plotting sheet
- Calculate the times (ship's and GMT) of sunrise, sunset and twilight.
- Determine the approximate azimuths and altitudes of the navigational stars and planets at twilight.
- Calculate and plot the lines of position obtained from
observations of several celestial bodies at twilight and thus find the
- Advance the LOP obtained from a sun sight to another LOP
obtained from the sun at a later time and find the boat's position
using a running fix (sun-run-sun).
- Calculate the true bearing of a low altitude celestial body in order to determine the error and deviation of the compass.