About this app
Study faster. Sail safer. Practice radar plotting, run bridge calculations, and master COLREGs, all in one app built for OOW prep and day-to-day reference. Designed for deck cadets, maritime students, and working officers (OOW, 3/O, 2/O). Radar plotting simulator: Add multiple targets with custom courses and speeds Automatic CPA/TCPA with clear high-risk warnings Relative motion vectors and target trails to visualise situations Training disclaimer: This simulator is for education only and must not be used for real-world navigation or collision-avoidance decisions. Calculation suite: Navigation: Speed–Time–Distance, ETA, Dead Reckoning, Course & Distance (Rhumb Line & Great Circle), Set & Drift & Fix Position Terrestrial & Celestial: Compass Error, Parallel Indexing, Object Distance, Advance & Transfer, Meridian Passage & LOP sight-reduction helper Stability & Ship Construction: FSE correction, Mean Draft, TPC/LCF usage, Trim & VCG Meteorology: True Wind, Barometer corrections, Beaufort scale converter & Tides and Currents Essential learning & reference library: Regulations: SOLAS, MARPOL, STCW, ISM Code, ISPS Code, GMDSS (quick-reference guides) Core nautical knowledge: Passage planning; ECDIS & charts; basic stability; compass deviation Procedures: Emergency procedures; SOPEP & SMPEP; checklists for safe watchkeeping; logbook entries; equipment handover Electronic navigation: AIS data interpretation; ECDIS functions; AIS/MMSI code reference Master the Rules of the Road (COLREGs): Shapes and sound signals International Code of Signals (ICOS) IALA buoyage systems (A & B) Test yourself & prep for exams: Flashcards, ICOS Hangman, and a Buoy Night-Light game OOW progress tracker. Who is it for? Maritime students & deck cadets: build a strong foundation Officers in training: prepare confidently for OOW certification Active deck officers: quick reference, calculation practice, and knowledge refreshers Anyone who wants to learn more about maritime and OOW Download Maritime Master - OOW and advance your maritime knowledge with confidence.
Latest release
What’s New
6-Month Content Review Every six months we re-check all learning content against the latest IMO conventions and this is that update. We've reviewed every reference page, calculator and quiz, and corrected what needed it: GMDSS sea areas (2024 SOLAS), COLREG distress signals, MARPOL discharge rules, the sunrise/sunset calculator and more. We've also added quick links to the full Maritime Master app family in the Info tab. Fair winds!
Audience growth
Ratings growth
Baseline captured. Growth appears after the crawler observes a changed rating count.
Momentum comes from crawler snapshots for the tracked storefront. “Viral growth signal” means unusually fast recent rating gains; it is an indicator, not download data.
Price tracking
Price intelligence
First snapshot captured. The trend line starts after the next crawler price observation.
- First observed Aug 24, 2026 · 3:58 AM $9.99