Comparison

Marinus vs Master

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

Head to head
About

Marinus

This app provides comprehensive guidance on maritime navigation rules and signals. It offers detailed information on flags, lights, sounds, and buoyage systems, along with interactive quizzes and a map feature. Designed for sailors, it ensures safe navigation on any vessel.

Highlights
  • Maritime flags and meanings
  • Weather scales and cloud identification
  • Sound signal guidance
  • Vessel navigation light diagrams
  • Day shape identification
  • Safe navigation maneuvers
  • Morse code decoder
  • IALA Buoyage System
  • Radio communication guidelines
  • COLREGs text
Features
Read full description

Not just another app for navigation rules… this is THE app for navigation rules! Created by sailors, for sailors, Marinus COLREGs is designed to provide clear and instant answers to your questions anytime, anywhere. It's the essential app for your sailboat or motorboat. Key Features: • Flags – All maritime flags with their meanings. • Meteo – Beaufort and Douglas scales, plus cloud identification. • Sounds – Navigate safely with sound signal guidance. • Lights – Detailed views of every vessel's navigation lights from all angles. • Day Shapes – Learn and identify the correct day shapes for any situation. • Maneuvers – Clear guidance on safe navigation maneuvers. • Morse – Decode Morse signals with ease. • Buoys (IALA) – Understand the International Buoyage System. • Radio – Key radio communication guidelines. • ColRegs – Full text of the International Regulations for Preventing Collisions at Sea (IRPCS). • Quiz – Test your knowledge with interactive quizzes. • Map – Visualize navigation concepts on an interactive map. Access PRO Features Unlock all PRO features with an affordable annual subscription. Your support helps us maintain and improve the app, keeping it the trusted tool for sailors around the world. Join thousands of sailors who trust Marinus ColRegs every day on their iPhone. Whether you're an experienced seafarer or just starting your nautical journey, this is the app you’ve been looking for! For any questions, feel free to contact us at info@marinus.es.

About

Master

Learn maritime navigation rules with an interactive system designed for effective retention. This app breaks down complex regulations into manageable sections with visual aids and mnemonics. It revisits incorrect answers and provides instant graphical feedback, making the learning process intuitive and efficient.

Highlights
  • Interactive learning system
  • Step-by-step rule guidance
  • Mnemonics and memory aids
  • Interactive visuals
  • Graphical feedback on answers
  • Practice section with progress tracking
Features
Currently charting
Read full description

Master-Nav is a progressive COLREGS learning system developed by a Master Mariner. The COLREGS are notoriously difficult to learn and retain — Master-Nav makes it significantly easier through an interactive system built around how your brain actually works. Instead of guessing through random question banks, Master-Nav guides you step by step through every rule from start to finish. Wrong answers are revisited until the rules stick — properly. Complex regulations are broken down into learnable chunks — bite-sized sections supported by mnemonics, memory aids and interactive visuals designed around how the brain actually retains information. Every incorrect answer is shown graphically alongside the correct one — immediately clear, no confusion. And with a single tap, the relevant COLREGS rule is accessible from any question at any time. Master-Nav covers COLREGS Parts A to D — General, Steering & Sailing, Lights & Shapes and Sound & Light Signals — plus Annex IV Distress Signals. Over 1000 questions in multiple formats, with a dedicated Practice Section that tracks right, wrong and unanswered so you always know where to focus. COLREGS — the easy way.

Screenshots

Marinus4 screens
Master4 screens

Verdict

The call

The clearest difference is price: Marinus at Free against Master's $1.99. Marinus also leads on iOS requirement (13.0 vs 15.0). Master's advantage is in-app purchases (none vs 1) and ads (none vs shown). On ratings volume 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

Marinus is free to download; Master costs $1.99 up front. Marinus sells 1 in-app purchase, starting at $8.99 per year. Master asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Master holds the better App Store score, 4.7 against 4.4. Both are backed by a comparable volume of ratings — 215 and 94 respectively. Written reviews point the same way: 65% of Marinus's written reviews are positive against 97% of Master's.

UpkeepUpdate frequency

Marinus ships an update every 5 weeks, Master fortnightly. The most recent releases landed on September 21, 2026 and September 22, 2026 respectively.

Scorecard9 real differences · 2 level
Marinus versus Master: the parameters behind the verdict, then further details
ParameterMarinusMaster
PriceFree — better$1.99
Rating4.4 (215 ratings)4.7 (94 ratings) — better
Positive reviews65.3% of reviews96.9% of reviews — better
Number of ratings215 — better94
Update frequencyEvery 5 weeksFortnightly — better
AdsYesNo — better
In-app purchasesYesNo — better
MonetizationFree with in-app purchases — betterPaid
Best chart rank—#148 — better
DevicesiPhone, iPodiPhone, iPod
Requires iOS13.0 — better15.0
Further details — not scored
Size113 MB117 MB
Age rating4+4+
DeveloperAlejandroPeterjohn Chisholm

Customer experience

Marinus

All ratings215 ratings
Positive87.0%
Neutral7.4%
Negative5.6%
Written reviews95 reviews
Positive65.3%
Neutral10.5%
Negative24.2%

Master

All ratings94 ratings
Positive94.7%
Neutral2.1%
Negative3.2%
Written reviews32 reviews
Positive96.9%
Neutral3.1%
Negative0.0%

Bugs and requests

Marinus

Reported bugs

4 issues
  • App not working, ads won't clear
  • App crashes frequently
  • Mistake with sounds
  • App crashes after 10-15 seconds

Requested features

7 requests
  • Settings for Buoyage A & B & combined
  • Search feature
  • Combine sounds and lights
  • Add tides information
  • More free version functionality
Show 2 more
  • More detail in maneuvers section
  • Lights with silhouette and head-on/stern-on views

Master

Not enough reviews yet to summarise bugs or requests.

In-app purchases

1 purchases

Marinus

Subscriptions1
  • Marinus PRO3 Days trial$8.991 Year
None

Master

No in-app purchases

Questions

Is Marinus free?
Marinus is free to download, with in-app purchases available.
Is Master free?
Master costs $1.99, with no in-app purchases.
Which has better reviews, Marinus or Master?
Master is rated higher. Marinus averages 4.4 out of 5 from 215 ratings, while Master averages 4.7 from 94 ratings.
Do Marinus or Master have ads?
Marinus shows ads; Master does not.
Which is updated more often, Marinus or Master?
Marinus ships an update every 5 weeks, and Master fortnightly. Most recently, Marinus was updated on September 21, 2026 and Master on September 22, 2026.

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