Practice COLREG, IALA & GMDSS

Free, complete COLREG, IALA and GMDSS study — without a paywall

Pick your starting point

• COLREG rules (1–38, Parts A–E)Every rule explained — head-on, crossing, overtaking, restricted visibility, lights, sounds.
• IALA buoyage (Region A & B)Lateral, cardinal, isolated-danger, safe-water, special and emergency-wreck marks.
• Lights & shapes (Part C)Every vessel-light variant from Rules 23–31 with 3D bow/stern/port/starboard views.
• Sound signals (Part D)Whistle, bell, gong, distress and fog signals — with audio for every pattern.
• GMDSS / GOC preparationFifteen modules: sea areas A1–A4, VHF-DSC, MF/HF, NAVTEX, EPIRB, SART, drills.
• Country-specific exam guidesPER, PNB, RYA Day Skipper / Yachtmaster, USCG OUPV, ICC, STCW II/1 and more.

Common questions before you start

Is IALACOLREG really free? What's the catch?

There is no catch. All study content, quizzes, simulations and country guides are free, with no email gate. The site is funded by Google AdSense banners that load only after you accept the cookie banner. No paid tier, no "premium" pages, no scraped certifications.

Will I pass my exam using only this site?

For the rules section of most recreational exams (PER, PNB, RYA Day Skipper, ICC, USCG OUPV), yes — provided you also run the full-length mock exams here and review every mistake. Practical exams (manoeuvres, navigation, chart work) still require a school or an instructor on the water.

Which exams do you cover?

PER, PNB, Patrón de Yate, Capitán de Yate (Spain); RYA Day Skipper, RYA Yachtmaster Coastal/Offshore (UK); ICC (UN ECE); USCG OUPV / Six-Pack (USA); STCW II/1 (international); SBF-See (Germany); Permis Côtier / Hauturier (France); Patente Nautica entro 12 miglia and senza limiti (Italy); Carta de Marinheiro / Patrão Local (Portugal); Klein Vaarbewijs I & II (Netherlands); Δίπλωμα Ταχυπλόου (Greece); Voditelj brodice (Croatia); Arrais / Mestre / Capitão Amador (Brazil).

Do you cover the US Inland Rules separately from international COLREGs?

The pages document the international COLREGs (Rule 1(a)). We flag the US Inland Rules differences inside the affected rule pages — for example, Rule 23 Inland adds a special flashing-yellow towing light. For the USCG exam you must know both texts; the Demarcation Lines published in 33 CFR 80 tell you which one applies where.

Can I download a PDF of the rules?

The IMO publishes the official PDF — we link to it from our sources page. Our pages are designed to be the practical study companion you cannot get from a PDF: 3D vessel models, audible signals, mistake-prone questions and a per-rule FAQ.