Global latest IRPCS / COLREGS training

The rules of the sea, finally learnable.

Master the International Regulations for Preventing Collisions at Sea (IRPCS) through bite-sized lessons, real-world scenarios, and adaptive quizzes - on every device, any time you're underway.

Get started - free See the library

All 41 rules covered

Works offline at sea

RYA & MCA aligned

Built alongside RYA Day Skipper Yachtmaster Theory MCA OOW STCW Refresh Powerboat L2 Commercial Endorsement

Features

Everything you need to actually understand the rules.

Not a PDF reader. Not a slideshow. A learning system that adapts to you, designed by skippers who got tired of reading the same paragraph fifteen times.

Every rule, explained

All 41 rules across Parts A-E, written in plain English with the official text, key takeaways, and examples.

Adaptive quizzes

Spaced-repetition tests that focus on what you haven't mastered. Five minutes a day moves the needle.

Lights & shapes drill

Pattern recognition for vessel lights and day shapes - at night, in fog, from any aspect.

Real-world scenarios

Crossing, overtaking, head-on. Decide the give-way vessel under real conditions, not a textbook diagram.

Offline first

Download the entire library before you cast off. No signal, no problem - works in every cabin and cockpit.

Exam-ready confidence

Cited from the source. Aligned with RYA Day Skipper, Yachtmaster, and MCA OOW theory syllabuses.

The library

The full COLREGS, structured like a syllabus.

Browse by part, drill into individual rules, and track exactly what you've mastered. Every rule includes the verbatim text, plain-English breakdown, and key takeaways - plus a "Practice rule" button so theory turns into instinct.

PART A

General

Rules 1-3. Application, responsibility, definitions.

100%

PART B

Steering & Sailing

Rules 4-19. Conduct of vessels in any condition of visibility.

35%

PART C

Lights & Shapes

Rules 20-31. Requirements for navigation lights and day shapes.

PART D

Sound & Light Signals

Rules 32-37. Sound and light signals between vessels.

PART E

Exemptions

Rules 38-41. Exemptions, verified positions, ratification.

In the app

Beautiful in the dark.

Dark by design and easy on tired eyes, whether you're swotting up below deck after a watch, working towards your exams, or keeping your knowledge up to date.

IRPCS home screen showing a learning streak, today's 10-question daily challenge, and quick links to quizzes and topics — **Your day, one glance** Streak, daily challenge, weak spots.

The rule library listing COLREGS rules by part, with International, U.S. Inland and Shared filters — **Every rule, structured** Filter Intl, U.S. Inland or Shared.

Practice screen with daily quizzes, a timed 50-question mock exam, and sound, lights and buoyage drills — **Practice that adapts** Daily sets, drills, timed mock exam.

A sound-signal question playing two short blasts and asking what the signal means — **Hear the signals** Real audio - blasts, bells, fog.

A lights and shapes question answered correctly, with the rule citation explaining the 112.5 degree sidelight arc — **Learn the why** Every answer cites its rule.

Reference page for a power-driven vessel underway at night, showing its lights with photoreal and vector views — **Lights, photoreal** Spot vessels as you'd really see them.

West cardinal mark reference page with photo, meaning, top mark and light characteristics — **Buoyage, decoded** IALA A & B marks with light rhythms.

Practice mode

Decide in seconds. Like you would on the water.

Multiple choice, scenarios, and rapid-fire light recognition. The app tracks every weak spot and quietly serves it back to you tomorrow.

Rule 15 · Crossing Question 4 of 10

Two power-driven vessels are crossing so as to involve risk of collision. What's the rule?

Why

Rule 15 - the vessel which has the other on her own starboard side keeps out of the way and shall, if circumstances of the case admit, avoid crossing ahead.

The competition

Why mariners are switching to IRPCS.

There's no shortage of ways to learn the COLREGS - a focused lights-and-shapes app, a paid flashcard site, or one chapter of a £250 RYA online course. IRPCS is the missing middle: every rule, adaptive practice, native mobile, free to start.

Feature	IRPCS	ColRegs: Nav Lights & Shapes	Learn The COLREGS	RYA Online Theory
COLREGS coverage	All 41 rules, Parts A-E	Part C only (lights & shapes)	Selected rules + flashcards	One module of a wider syllabus
Adaptive practice	Spaced repetition	Random quiz	Random daily quizzes	Linear lessons, no quiz mode
Lights & shapes drill	Live pattern recognition	Static graphics + quiz	550+ flashcards	Course slides only
Native iOS + Android	Both platforms	iOS only	Web only	Web only
Works offline at sea	Full library cached	Yes	Online only	Online only
RYA / MCA alignment	Both, instructor-verified	Not stated	Both referenced	Sets the RYA syllabus
Pricing	Free start (Parts A & B)	$3.99 one-time	One-time paid	£236+ per course

Comparison reflects publicly stated features as of April 2026. Sources: developers' websites and App Store listings.

Giving back

10% goes back to Search and Rescue.

The people who'd come for us are volunteers - so each year we donate 10% of IRPCS profits to volunteer maritime SAR charities. Premium subscribers choose where their share goes, right in the app.

RNLI US Coast Guard Foundation Surf Life Saving Australia Canadian Lifeboat Institution Coastguard NZ

Donations are made annually, attributed to each subscriber's chosen charity at the time of our year-end donation report.

FAQ

Questions, answered honestly.

Is the IRPCS app free?

Yes - Parts A and B (Rules 1-19) are free forever, including practice quizzes for those rules. The full library and adaptive practice across all 41 rules unlock with a one-time purchase or affordable subscription.

Does it work offline at sea?

Yes. The entire rule library, lessons, lights & shapes drills, and quizzes work without a connection. Download once on shore and you're set for the longest passage.

Is this aligned to RYA, MCA, or USCG syllabuses?

We map content to RYA Day Skipper, Coastal Skipper, Yachtmaster (theory), and MCA OOW theory. The COLREGS themselves are an international standard - the same rules apply whether you're sitting a UK, EU, or US ticket.

Who built this?

A small team of working skippers, instructors, and software builders who got tired of poorly-designed maritime training apps. Every lesson is reviewed by qualified instructors before publishing.

How is this different from reading the IMO publication?

The IMO booklet is the source of truth, and we cite it verbatim on every rule. But the rules are written in legal prose. We add plain-English breakdowns, scenarios, visual aids for lights and shapes, and a structured way to actually retain it all.

Can I use it during a course?

Absolutely - many of our users use IRPCS alongside formal training. It's a complement to instructor-led courses, not a replacement for the assessment itself.

Is my progress synced between devices?

Yes. Sign in with Apple or Google and your progress, weak-spot tracking, and bookmarks sync between iPhone, iPad, and Android.

What about updates to the COLREGS?

When IMO publishes amendments, we update the app within days and notify you of what's changed and why it matters. The current edition is reflected throughout.

Download IRPCS. Sail with confidence.

Free to start. No credit card. Works on iPhone, iPad and Android.

Download on theApp Store Get it onGoogle Play

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