Comparison

Cortex Onboard vs EZ Celestial Navigation

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Cortex Onboard

Configure and update your marine electronics, and monitor vital boat data remotely. Receive alerts, view AIS information, and manage anchor watch from your mobile device.

Highlights
  • Configure and update Cortex devices
  • View AIS information and alerts
  • Manage Anchor Watch remotely
  • Monitor boat sensors and NMEA 2000 instruments
  • View battery, pressure, and position data
Read full description

Cortex Onboard is free with your Cortex. Use it to configure your Cortex Hub and download updates to your Cortex devices with new features and improvements. You can also use Cortex Onboard to receive and manage alerts, view AIS information and instrument data anywhere on board your boat. View out-of-the-box sensors or NMEA 2000 networked instruments. - Setup is easy and free. - Use Cortex Onboard to configure and update your Cortex devices easily. - View AIS information and receive alerts on board direct to your device. - Manage Anchor Watch from the palm of your hand anywhere on board. - Use the Cortex Hub’s built-in sensors for battery level, barometric pressure and boat position. - Connect your Cortex Hub to NMEA 2000, or an external sensor, to add monitoring for wind, depth, bilge high water, temperature, shore power or security. - The Cortex Hub supports up to 10 WiFi devices (includes Handsets).

About

EZ Celestial Navigation

This app simplifies celestial navigation using a sextant, providing tools to calculate your position at sea. It offers automated calculations or manual table access, with features for observation archiving and compass checks. Ideal for learning and practicing traditional navigation methods.

Highlights
  • Automated sight reduction and LOP plotting
  • Manual Nautical Almanac and Pub. 229 table access
  • Observation archiving and restoration
  • Compass check functionality
  • Printable Nautical Almanac pages and reports
  • Universal app for iOS and macOS
Features
Currently charting
Read full description

Celestial navigation has never been easier! With ezAlmanacOne and a sextant you will be finding your fix like a pro in no time! ezAlmanacOne is an evolution of the iPad version of ezAlmanac with the modern user interface used in the Windows 10 version of ezAlmanac. All of the features of ezAlmanac plus new features including: - Universal app runs on iPad, iPhone, iPod touch, and the new MacBook with M1 processor. - Supports all device orientations. All screens support zoom and pan. - Make bearing observations to perform compass checks. - Archive saved observations and restore observation data from an archive. - Includes quick start guide, usage examples, and other documentation to learn celestial navigation. - Print/Output Nautical Almanac pages, observation reports, and other app documentation. 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! Besides finding your fix, ezAlmanacOne is one of the best tools available to perform compass checks from a bearing observation of one of the navigational bodies. The compass check function supports checking up to 5 devices from a single bearing observation. ezAlmanacOne will also create a report of your compass check that can be saved as a PDF file or printed for the ships records. Celestial navigation instructors love ezAlmanacOne because it does celestial navigation exactly as they teach it. Values obtained from the Nautical Almanac and Pub. 229 are clearly identified with an icon of the book. When you press the book icon you are taken to the page that has that value with the row, column and value highlighted. Even when ezAlmanacOne is doing all the work, it can teach you how to do it manually using the books. For manual celestial navigation you can generate and print Nautical Almanac pages to use as a backup on a passage. You can even print the sight reduction forms and plotting sheets you will need. ezAlmanacOne performs all astronomical calculations using the NOVAS 3.1 software from the US Naval Observatory (USNO) and a JPL ephemeris that covers the years 1960 through 2059. It also implements WMM-2020, the latest World Magnetic Model software available from NOAA, to compute magnetic declination. Since all calculations are performed in the software, ezAlmanacOne is fully functional with no dependency on the internet.

Screenshots

Cortex Onboard4 screens
EZ Celestial Navigation4 screens

Verdict

The call

The clearest difference is price: Cortex Onboard at Free against EZ Celestial Navigation's $29.99. EZ Celestial Navigation's advantage is review sentiment (100% vs 56%) and rating (4.9 vs 3.8). On ratings volume, ads, in-app purchases and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Cortex Onboard is free to download; EZ Celestial Navigation costs $29.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

EZ Celestial Navigation holds the better App Store score, 4.9 against 3.8. Both are backed by a comparable volume of ratings — 12 and 26 respectively. Written reviews point the same way: 56% of Cortex Onboard's written reviews are positive against 100% of EZ Celestial Navigation's.

UpkeepUpdate frequency

Cortex Onboard ships an update every 2 months, EZ Celestial Navigation monthly. Both last shipped on November 3, 2026.

Scorecard7 real differences · 4 level
Cortex Onboard versus EZ Celestial Navigation: the parameters behind the verdict, then further details
ParameterCortex OnboardEZ Celestial Navigation
PriceFree — better$29.99
Rating3.8 (12 ratings)4.9 (26 ratings) — better
Positive reviews55.6% of reviews100.0% of reviews — better
Number of ratings1226 — better
Update frequencyEvery 2 monthsMonthly — better
AdsNoNo
In-app purchasesNoNo
MonetizationFree — betterPaid
Best chart rank—#55 — better
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS18.513.0 — better
Further details — not scored
Size22 MB153 MB
Age rating4+4+
DeveloperGarmin New Zealand LtdEZ Celestial LLC

Customer experience

Cortex Onboard

All ratings12 ratings
Positive66.7%
Neutral8.3%
Negative25.0%
Written reviews9 reviews
Positive55.6%
Neutral11.1%
Negative33.3%

EZ Celestial Navigation

All ratings26 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews4 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Cortex Onboard

No in-app purchases

None

EZ Celestial Navigation

No in-app purchases

Questions

Is Cortex Onboard free?
Cortex Onboard is free to download, with no in-app purchases.
Is EZ Celestial Navigation free?
EZ Celestial Navigation costs $29.99, with no in-app purchases.
Which has better reviews, Cortex Onboard or EZ Celestial Navigation?
EZ Celestial Navigation is rated higher. Cortex Onboard averages 3.8 out of 5 from 12 ratings, while EZ Celestial Navigation averages 4.9 from 26 ratings.
Do Cortex Onboard or EZ Celestial Navigation have ads?
Neither Cortex Onboard nor EZ Celestial Navigation shows ads.
Which is updated more often, Cortex Onboard or EZ Celestial Navigation?
Cortex Onboard ships an update every 2 months, and EZ Celestial Navigation monthly. Most recently, Cortex Onboard was updated on November 3, 2026 and EZ Celestial Navigation on November 3, 2026.

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