EZ Celestial Navigation vs Rule Master
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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.
- 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
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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.
Rule Master
Master maritime navigation rules with this comprehensive quiz app. It offers extensive question banks, custom filters, and detailed progress tracking for both new and experienced sailors. Generate custom exams and access a digital handbook for efficient learning and exam preparation.
- 10,000+ question-answer combinations
- Custom question filters
- Fill-in-the-blank questions
- Offline capability
- Exam PDF generation
- Digital Navigation Rules handbook
- Progress tracking and statistics
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The most advanced, modern, and competitive Rules of the Road quiz application on the iOS App Store! This Navigation Rules quiz application is a must-have for new and experienced sailors, alike. This complete Rules of the Road toolbox is the most effective way to build and maintain proficiency, so you can spend less time preparing for your next USCG Navigation Rules examination. Track your progress like never before, and use our advanced question filters and rule proficiency statistics for efficient, targeted studying. Are you an instructor? Generate and print beautiful, custom-filtered COLREG examinations in seconds with our advanced exam PDF generation algorithm. Are you an experienced mariner? There is always more to learn! Rule Master provides 100+ hand-selected, fill-in-the-blank questions optimized to refine your mastery of the Rules of the Road. Mastery of these verbatim COLREG excerpts allows for intelligent verbal communication of the rules — especially useful for students undergoing rigorous training at the USN Mariner Skills Training Command. - 10,000+ question-answer combinations - Advanced, custom question filters for targeted studying - 100+ hand-selected, fill-in-the-blank questions for experienced Mariners - Full offline capability - Unlimited exam PDF generation and printing - Full, digital Navigation Rules handbook for quick reference - In-depth progress tracking and statistics This COLREG application's abbreviated question bank -- tediously hand-scrubbed and optimized by an experienced USN Surface Warfare Officer -- is coupled with a custom algorithm that generates 10,000+ unique question-answer combinations specifically designed to more effectively teach and examine student knowledge while simultaneously exposing students to the confusing vernacular commonly found in the infamous USCG Rules of the Road question bank.
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Verdict
EZ Celestial Navigation and Rule Master both sit at 4.9 stars, but that hides the real split: 100% of EZ Celestial Navigation's written reviews are positive against 43% of Rule Master's. EZ Celestial Navigation also leads on update cadence (monthly vs every 3 months) and device support (3 vs 1). Rule Master's advantage is price ($9.99 vs $29.99) and ratings volume (292 vs 26). On rating, ads and in-app purchases 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
EZ Celestial Navigation costs $29.99 and Rule Master $9.99 up front. Neither carries in-app purchases, so what you see is what you pay.
On the App Store both sit at effectively the same score — 4.9 for EZ Celestial Navigation against 4.8 for Rule Master. That said, the two scores are not equally well evidenced: Rule Master has 292 ratings behind it against 26, so its average is the more settled of the two. Written reviews are what separate them: 100% of EZ Celestial Navigation's written reviews are positive against 43% of Rule Master's.
EZ Celestial Navigation ships an update monthly, Rule Master every 3 months. The most recent releases landed on October 3, 2026 and October 11, 2026 respectively.
| Parameter | EZ Celestial Navigation | Rule Master |
|---|---|---|
| Price | $29.99 | $9.99 — better |
| Rating | 4.9 (26 ratings) — better | 4.8 (292 ratings) |
| Positive reviews | 100.0% of reviews — better | 42.9% of reviews |
| Number of ratings | 26 | 292 — better |
| Update frequency | Monthly — better | Every 3 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Free with in-app purchases — better |
| Best chart rank | #153 | #19 — better |
| Devices | iPhone, iPad, iPod — better | iPhone |
| Requires iOS | 13.0 — better | 16.0 |
| Further details — not scored | ||
| Size | 153 MB | 13 MB |
| Age rating | 4+ | 4+ |
| Developer | EZ Celestial LLC | Universal Queue LLC |
Customer experience
EZ Celestial Navigation
Rule Master
Bugs and requests
EZ Celestial Navigation
Not enough reviews yet to summarise bugs or requests.
Rule Master
Reported bugs
5 issues- Questions disappear off the bottom of the screen
- Diagrams are too small to identify vessels
- Some questions have character limits over the margin
- App doesn't display quiz and verbatim in a usable manner
- Incomplete questions showing three dots (...)
Requested features
4 requests- Link relevant COLREG rule when answering correctly and incorrectly
- Expand subjects to include chemistry or history
- Improvements in tracking missed questions for training
- Display full question text when it's cut off
In-app purchases
EZ Celestial Navigation
No in-app purchases
Rule Master
No in-app purchases
Questions
Is EZ Celestial Navigation free?
Is Rule Master free?
Which has better reviews, EZ Celestial Navigation or Rule Master?
Do EZ Celestial Navigation or Rule Master have ads?
Which is updated more often, EZ Celestial Navigation or Rule Master?
Which is more popular, EZ Celestial Navigation or Rule Master?
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