Comparison

Celestial Nav vs Nautical Rules

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

Head to head
About

Celestial Nav

This app provides tools for celestial navigation, offering computations for celestial bodies and sight reductions. It includes an offline perpetual almanac and allows for quick capture of observation data for accurate course adjustments.

Highlights
  • Celestial navigational computations
  • Offline perpetual almanac
  • Quick celestial observation data capture
  • High accuracy sight reductions
  • Sight planning and reduction tools
  • Celestial fix computations
Features
Read full description

We believe celestial navigation is an amazing skill and develop Celestial Nav to offer a simple, yet powerful and all encompassing app for our users. Celestial Nav is an easy to use, all-in-one tool which offers: • Celestial navigational computations for your device • Simple toolbar menu for quick access • Internally stored perpetual Almanac • Offline ready and functional without the need for other external tools • Quick and easy capture celestial observation data • High accuracy sight reductions • Star reference tables SIGHT PLANNING • Local Hour Angle (LHA) for Aries • Star tables sorted by name, magnitude, declination, and SHA • Sunrise, sunset, twilight, and location reference • Moon phase reference SIGHT REDUCTION • High accuracy sight reduction algorithm • Perpetual Almanac offering accurate data for years 1600 - 3000 • Almanac data for Sun, Moon, Mercury, Venus, Mars, Jupiter, Saturn • Detailed Almanac data for 58 navigational stars • Assumed Position (AP) for any user defined position • Line of Position (LOP) intercept data for accurate course and speed adjustments • Computational variables displayed for accuracy and validation CELESTIAL FIX • Computations by USNO algorithm in the Nautical Almanac • Save all your LOP in an easy reference table BASIC VERSION Free daytime celestial navigation tools using the sun: • Unlimited sextant sight reduction calculations • Sight reduction to a line of position using the sun • Perpetual almanac for the sun • Advanced sight corrections for index error, eye height, temperature, and pressure • Support for upper and lower limb reference • Star Table with navigational references • Detailed Sun references • Limited Moon references PRO FEATURES (IN-APP PURCHASE) Advanced Day & Night Celestial Navigation includes all BASIC features plus: • Almanac data for 65 navigational bodies for years 1600 through 3000 • Map display for saved LOPs • View intercepts with course and speed corrections • Metric and imperial unit support with automatic conversions • Support for coordinate entries in different formats (H° M’ S” or Decimals) • Save all your LOP calculations for future reference • Save user preferences and settings • Unrestricted moon references • Almanac and algorithmic models for 65 navigational bodies: • Sun, Moon, Mercury, Venus, Mars, Jupiter, and Saturn • 58 navigational stars Supported stars: Acamar, Achernar, Acrux, Adhara, Aldebaran, Alioth, Alkaid, Alnair, Alnilam, Alphard, Alphecca, Alpheratz, Altair, Ankaa, Antares, Arcturus, Atria, Avior, Bellatrix, Betelgeuse, Canopus, Capella, Deneb, Denebola, Diphda, Dubhe, Elnath, Eltanin, Enif, Fomalhaut, Gacrux, Gienah, Hadar, Hamal, Kaus Australis, Kochab, Markab, Menkar, Menkent, Miaplacidus, Mirfak, Nunki, Peacock, Polaris, Pollux, Procyon, Rasalhague, Regulus, Rigel, Rigil Kent., Sabik, Schedar, Shaula, Sirius, Spica, Suhail, Vega, Zubengenubi REFERENCES Sight reductions and celestial calculations use various internationally accepted references for the most accurate results: • Jean Meeus - Astronomical Algorithms • US Naval Observatory (USNO) Almanac and Algorithms • Hipparcos New Astrometric Catalog, Published 2007 • ELP2000-85 SUBSCRIPTION TERMS Celestial Nav is free to download and the basic features free to use. A paid upgrade to the PRO version provides access to premium features and additional tools. We may offer trial subscriptions that give limited time access to all PRO features and premium content for the duration of the trial period. Trial subscriptions automatically expire and the app will revert back to the Basic version thereafter. No data is lost but access and use of premium features will no longer be available.

About

Nautical Rules

Master USCG Navigation Rules with a comprehensive question bank and smart study features. Track your progress, practice for exams, and study offline to navigate with confidence.

Highlights
  • 1,200+ practice questions
  • Inland and International waters coverage
  • Detailed explanations
  • Customizable tests
  • Offline study capability
  • Progress tracking dashboard
  • Accuracy by rule statistics
Read full description

Nautical Rules is the ultimate study companion for mastering the USCG Navigation Rules (COLREGS). Whether you're preparing for your captain's license exam or refreshing your maritime knowledge, this app provides everything you need to succeed. COMPREHENSIVE QUESTION BANK - Over 1,200 practice questions covering all Navigation Rules - Questions for both Inland and International waters - Covers Steering & Sailing Rules, Lights & Shapes, Sound Signals, and more - Detailed explanations SMART STUDY FEATURES - Take customizable tests with 10, 25, 50, or 100 questions - Practice mode with immediate feedback and explanations - Focus Area suggestions to target your weakest rules - Bookmark questions for later review - Review your mistakes to reinforce learning TRACK YOUR PROGRESS - Activity dashboard with test history and statistics - See your accuracy by rule (Rule 1, Rule 2, etc.) - Track your study streak and mastery level - View detailed results for each completed test DESIGNED FOR MARINERS - Clean, intuitive interface optimized for study sessions - No internet connection required - study anywhere - All questions based on official USCG Navigation Rules - Perfect for captains, SWO, sailors, and maritime professionals Whether you're studying for the USCG license exam, improving your seamanship skills, or just want to stay sharp on the water, Nautical Rules gives you the tools to succeed. Download now and navigate with confidence! --- Note: This app is an educational study aid and is not affiliated with or endorsed by the U.S. Coast Guard. For official rules and regulations, consult the official USCG Navigation Rules publications.

Screenshots

Celestial Nav4 screens
Nautical Rules4 screens

Verdict

The call

The clearest difference is rating: Nautical Rules at 5.0 against Celestial Nav's 4.3. Nautical Rules also leads on review sentiment (100% vs 64%) and in-app purchases (none vs 6). Celestial Nav's advantage is iOS requirement (15.0 vs 17.0). On price, ratings volume, update cadence and ads 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

Both are free to download. Celestial Nav sells 6 in-app purchases, starting at $1.99 per month. Nautical Rules asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Nautical Rules holds the better App Store score, 5.0 against 4.3. Both are backed by a comparable volume of ratings — 10 and 4 respectively. Written reviews point the same way: 64% of Celestial Nav's written reviews are positive against 100% of Nautical Rules's.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly every 3 weeks. The most recent releases landed on October 1, 2026 and October 6, 2026 respectively.

Scorecard5 real differences · 5 level
Celestial Nav versus Nautical Rules: the parameters behind the verdict, then further details
ParameterCelestial NavNautical Rules
PriceFreeFree
Rating4.3 (10 ratings)5.0 (4 ratings) — better
Positive reviews64.3% of reviews100.0% of reviews — better
Number of ratings10 — better4
Update frequencyEvery 3 weeksEvery 3 weeks
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesFree — better
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.0 — better17.0
Further details — not scored
Size20 MB5 MB
Age rating4+4+
DeveloperSkytip LLCJoseph Kim

Customer experience

Celestial Nav

All ratings10 ratings
Positive80.0%
Neutral10.0%
Negative10.0%
Written reviews14 reviews
Positive64.3%
Neutral7.1%
Negative28.6%

Nautical Rules

All ratings4 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews9 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

6 purchases

Celestial Nav

Subscriptions3
  • PRO Version$1.991 Month
  • PRO Version$7.996 Months
  • PRO Version$9.991 Year
One-time3
  • 7 Day Trial License$0.99
  • 30 Day Trial License$2.99
  • PRO Version Lifetime$24.99
None

Nautical Rules

No in-app purchases

Questions

Is Celestial Nav free?
Celestial Nav is free to download, with in-app purchases available.
Is Nautical Rules free?
Nautical Rules is free to download, with no in-app purchases.
Which has better reviews, Celestial Nav or Nautical Rules?
Nautical Rules is rated higher. Celestial Nav averages 4.3 out of 5 from 10 ratings, while Nautical Rules averages 5.0 from 4 ratings.
Do Celestial Nav or Nautical Rules have ads?
Neither Celestial Nav nor Nautical Rules shows ads.
Which is updated more often, Celestial Nav or Nautical Rules?
Celestial Nav ships an update every 3 weeks, and Nautical Rules every 3 weeks. Most recently, Celestial Nav was updated on October 1, 2026 and Nautical Rules on October 6, 2026.

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