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EZ Nautical Almanac (ezNA)

This could be the last Nautical Almanac you will ever need to buy!

EZ Nautical Almanac is a digital nautical almanac that generates nautical almanac pages for the years 1960 - 2059.  All data is formatted as you are used to seeing in the USNO and HMNAO nautical almanacs.  It includes functions to perform basic nautical almanac tasks.

EZ Nautical Almanac DOES include the NAO Concise Sight Reduction tables and demonstrates their usage in the Sight Reduction function.  Note that ezAlmanacOne performs sight reductions using the Pub 229 tables and does not offer the NAO tables at this time.

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 app functions to find event times or do a sight reduction, values used from the almanac are identified with an almanac button.  Press the button to see the value highlighted on the Nautical Almanac page.

Find Event Times

Determine Sun, Moon, and planet event times (rise, set meridian, etc) for the selected date and location using techniques and values from the Nautical Almanac.

Perform a Sight Reduction

Enter all inputs for the observation (DR Position, Time Zone, Date and Time, Object, and Object Altitude) and all steps to perform the sight reduction are done for you - showing you all values used along the way.

Since the sight reduction uses the included NAO Concise Sight Reduction tables, this is a great way to get familiar with using these tables.

Please note that ezNA does NOT include any ability to save the observation and use it to find a fix.  It is only a digital nautical almanac with functions to help you access the data.

The ezAlmanacOne app is our complete celestial navigation solution.

NAO Concise Sight Reduction Tables

I tested the NAO Concise Sight Reduction tables by building a test ezAlmanacOne build that calculated reductions for both sets of tables - Pub 229 and NAO.  I then implemented a toggle in LOP Plot function allowing me to switch back and forth between the two when plotting the LOPs.

Since ezAlmanacOne allows loading saved data from a file, I was able to test with the data files saved when making the "Detailed Solutions" books.

The results were amazing! Toggling between the tables showed very minimal differences at the 100NM X 100NM zoom level.  The differences were more noticable at the 10NM X 10NM zoom but not really enough to change the selected fix in my opinion.

I did run all 100 problems and verified similar results. The LOP results of 3 problems from the first trip are shown here.


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.

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