Comparison

Marinus vs Seabook+

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

Seabook+

This app provides comprehensive maritime information for professionals and enthusiasts. It offers tools for navigational and technical computations, designed for easy use at sea with offline accessibility and a user-friendly interface.

Highlights
  • Comprehensive maritime information
  • Navigational and technical computations
  • Offline accessibility
  • User-friendly interface
  • Information for marine professionals
  • Knowledge for sea enthusiasts
Features
Read full description

Seabook is an information and knowledge source for marine professionals, sailors as well as sea enthusiasts. Seabook Master contains comprehensive and detailed information on the profession. Seabook fits to use at sea with offline accessibility and best user interface. The tools help navigational and technical computations and conversations at ease.

Screenshots

Marinus4 screens
Seabook+4 screens

Verdict

The call

The clearest difference is price: Marinus at Free against Seabook+'s $6.99. Marinus also leads on update cadence (every 5 weeks vs every 35 months) and ratings volume (215 vs 2). Seabook+'s advantage is rating (5.0 vs 4.4) and in-app purchases (none vs 1). On review sentiment, device support and iOS requirement 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; Seabook+ costs $6.99 up front. Marinus sells 1 in-app purchase, starting at $8.99 per year. Seabook+ asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Seabook+ holds the better App Store score, 5.0 against 4.4. That said, the two scores are not equally well evidenced: Marinus has 215 ratings behind it against 2, so its average is the more settled of the two. Written reviews complicate that: 65% of Marinus's written reviews are positive against 62% of Seabook+'s, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

Marinus ships an update every 5 weeks, Seabook+ every 35 months. The most recent releases landed on September 26, 2026 and September 24, 2026 respectively.

Scorecard7 real differences · 3 level
Marinus versus Seabook+: the parameters behind the verdict, then further details
ParameterMarinusSeabook+
PriceFree — better$6.99
Rating4.4 (215 ratings)5.0 (2 ratings) — better
Positive reviews65.3% of reviews — better61.5% of reviews
Number of ratings215 — better2
Update frequencyEvery 5 weeks — betterEvery 35 months
AdsYesNo — better
In-app purchasesYesNo — better
MonetizationFree with in-app purchases — betterPaid
DevicesiPhone, iPodiPhone, iPad, iPod — better
Requires iOS13.013.0
Further details — not scored
Size113 MB37 MB
Age rating4+12+
DeveloperAlejandroOzgur GUNES

Customer experience

Marinus

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

Seabook+

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews13 reviews
Positive61.5%
Neutral7.7%
Negative30.8%

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

Seabook+

Not enough reviews yet to summarise bugs or requests.

In-app purchases

1 purchases

Marinus

Subscriptions1
  • Marinus PRO3 Days trial$8.991 Year
None

Seabook+

No in-app purchases

Questions

Is Marinus free?
Marinus is free to download, with in-app purchases available.
Is Seabook+ free?
Seabook+ costs $6.99, with no in-app purchases.
Which has better reviews, Marinus or Seabook+?
Seabook+ is rated higher. Marinus averages 4.4 out of 5 from 215 ratings, while Seabook+ averages 5.0 from 2 ratings.
Do Marinus or Seabook+ have ads?
Marinus shows ads; Seabook+ does not.
Which is updated more often, Marinus or Seabook+?
Marinus ships an update every 5 weeks, and Seabook+ every 35 months. Most recently, Marinus was updated on September 26, 2026 and Seabook+ on September 24, 2026.

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