Celestial navigation has never been easier! With ezAlmanacOne and a sextant you will be finding your fix like a pro in no time!

ezAlmanacOne will help you perform celestial navigation exactly as it has been done for hundreds of years. It produces all Nautical Almanac (1960-2059) and Pub. 229 tables exactly as you are used to seeing them in the printed form. All tables can be accessed directly for manual usage if you choose to do so. Since they are produced by the software they support zooming and panning, and you can highlight in the tables to easily find the correct value to use.


Most users, however, will prefer to let ezAlmanacOne do all of the work. Simply enter the basic sight parameters, make and enter your observations, and ezAlmanacOne will do the rest. It performs all of the steps to correct your observation, find GP of the object, do the sight reduction, and plot the LOP. No steps are skipped and all details are shown. Click where the LOPs cross in the plot and you have found your fix!

Nautical Almanac Pages

Generate 100 years of Nautical Almanac pages from 1960 to 2059.

Use them directly from the app for manual celestial navigation.  All pages support zoom, pan, and highlighting to easily find the value to use - even when using a phone.

Pages can be printed for use outside the app or as a backup on a passage.

When using other app functions to do the celestial navigation work, values used from the almanac are identified with an almanac button.  Press the button to see the value highlighted on the Nautical Almanac page.

Pub 229 Pages

Generate all pages and interpolation tables for all 6 volumes of Pub 229.

Like the almanac pages, use them directly from the app for manual celestial navigation.  All pages support zoom, pan, and highlighting to easily find the value to use - even when using a phone.

When using other app functions to do the sight reduction, values used from Pub. 229 are identified with a Pub. 229 button.  Press the button to see the value highlighted on the Pub. 229 page.

Make Observations

Determine Sun, Moon, and planet event times for the current date and location using techniques and values from the Nautical Almanac.

Select the best times to make your celestial navigation observations using the animated star map.  View location and movement of the navigational bodies for the selected date.

After making your altitude observations (Hs), automatically correct them to produce Ha and Ho needed for the sight reduction using values from the Nautical Almanac.

Verify your observations against an internally calculated altitude profile.

Automatically find the GHA and Declination values at the time of the observation using values from the Nautical Almanac.

Find Your Fix

Observations are automatically reduced showing all values used from Pub 229.

The sight reductions are automatically plotted just as you would do it manually. Click or tap the plot where the lines of position cross to find your fix.

Press the "Map View" button to display the reductions plated on a map with full zoom and pan capability.

Print fix reports showing a summary of all inputs and outputs, plot of the LOPS, and all observation and reduction data displayed in a sight reduction form.

Compass Checks

Make a bearing observation of one of the navigational bodies and enter the current heading of up to 5 devices.

The azimuth of the observed object is automatically calculated using GHA and Dec values from the Nautical Almanac at the time of the observation.

The gyro error or deviation for each device is automatically calculated from the heading differences between the observation device and the device being checked.

Generate compass checks reports for the ships records.


ezAlmanacOne includes a "Quick Start Guide" and a step-by-step "Usage Examples" document that will get you using the app right away.

To delve deeper and really learn celestial navigation,  the celestial navigation section (Part 3) of Nick de Munnik's book "Practical Navigation Illustrated" is available for use right from the app.

ezAlmanacOne uses Pub. 229 for the sight reduction step.  A reprint of the introduction section of these tables is also available from the app for full details of the table usage.


ezAlmanacOne for Android


The Android version of ezAlmanacOne is almost here! Watch for it on the Google Play Store this Spring.



ezAlmanacOne for iOS Released


Version 1.1.1 of ezAlmanacOne for iOS was released to the Apple App Store on 3/3/2021.  This is a universal app that will run on all iOS devices and the new MacBook with M1 processor.



EZ Celestial LLC

Glendale, Arizona USA

Email: support@ezcelestial.com