# Marinus vs Seabook+

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.

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.

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.

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.

## The numbers

| Metric | Marinus | Seabook+ |
| --- | --- | --- |
| Price | **Free** | $6.99 |
| Rating | [4.4 (215 ratings)](https://appshunter.io/ios/app/marinus-maritime-rules/id536108872/reviews) | **[5.0 (2 ratings)](https://appshunter.io/ios/app/seabook-plus/id1517249755/reviews)** |
| Number of ratings | **215** | 2 |
| Positive reviews | **65.3% of reviews** | 61.5% of reviews |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | **Every 5 weeks** | Every 35 months |
| Monetization | **Free with in-app purchases** | Paid |
| Size | 113 MB | 37 MB |
| Requires iOS | 13.0 | 13.0 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 12+ |
| Developer | [Alejandro](https://appshunter.io/developer/476976572) | [Ozgur GUNES](https://appshunter.io/developer/708215144) |

## What reviewers say

### Marinus

[App page](https://appshunter.io/ios/app/marinus-maritime-rules/id536108872)

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:** macOS Compatibility, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Marinus PRO | $8.99 | per year |

**What reviewers like**

- 👍 Great app for learning
- 👍 Useful study aid
- 👍 Very helpful for mariners
- 👍 Good information provided
- 👍 Easy to use

**What reviewers complain about**

- 👎 Swamped with ads
- 👎 Broken app functionality
- 👎 Subscription model is a money grab
- 👎 Lifetime pro withdrawn
- 👎 Scam for changing to subscription

**Reported bugs**

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

**Requested features**

- Settings for Buoyage A & B & combined
- Search feature
- Combine sounds and lights
- Add tides information
- More free version functionality


### Seabook+

[App page](https://appshunter.io/ios/app/seabook-plus/id1517249755)

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:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked 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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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*