Seabook+ vs Master
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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.
- Comprehensive maritime information
- Navigational and technical computations
- Offline accessibility
- User-friendly interface
- Information for marine professionals
- Knowledge for sea enthusiasts
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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.
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.
- Interactive learning system
- Step-by-step rule guidance
- Mnemonics and memory aids
- Interactive visuals
- Graphical feedback on answers
- Practice section with progress tracking
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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
Verdict
The clearest difference is review sentiment: Master at 97% against Seabook+'s 62%. Master also leads on update cadence (fortnightly vs every 35 months) and price ($1.99 vs $6.99). Seabook+'s advantage is rating (5.0 vs 4.7) and iOS requirement (13.0 vs 15.0). On ads, in-app purchases, monetization model 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
Seabook+ costs $6.99 and Master $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Seabook+ holds the better App Store score, 5.0 against 4.7. That said, the two scores are not equally well evidenced: Master has 94 ratings behind it against 2, so its average is the more settled of the two. Written reviews complicate that: 62% of Seabook+'s written reviews are positive against 97% of Master's, so the app with the better star average is not the one people write more warmly about.
Seabook+ ships an update every 35 months, Master fortnightly. The most recent releases landed on September 24, 2026 and September 22, 2026 respectively.
| Parameter | Seabook+ | Master |
|---|---|---|
| Price | $6.99 | $1.99 — better |
| Rating | 5.0 (2 ratings) — better | 4.7 (94 ratings) |
| Positive reviews | 61.5% of reviews | 96.9% of reviews — better |
| Number of ratings | 2 | 94 — better |
| Update frequency | Every 35 months | Fortnightly — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Devices | iPhone, iPad, iPod — better | iPhone, iPod |
| Requires iOS | 13.0 — better | 15.0 |
| Further details — not scored | ||
| Size | 37 MB | 117 MB |
| Age rating | 12+ | 4+ |
| Developer | Ozgur GUNES | Peterjohn Chisholm |
Customer experience
Seabook+
Master
In-app purchases
Seabook+
No in-app purchases
Master
No in-app purchases









