COLREG 72: Rules of the Road

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3.4K reviews
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Everyone
100K+
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Content rating
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About this app

COLREG 72 is a study and reference app for the maritime Rules of the Road and USCG exam prep: International rules (COLREGs) and US Inland Navigation Rules (33 CFR 83) side by side, navigation lights, day shapes and sound signals, practice exams and sample examinations based on public USCG/NMC samples. US Inland and the sample examinations appear with the region set to United States and English as the app language.

COLREG 72 is an independent study app and does not represent any government entity. It is not affiliated with or endorsed by the IMO, the U.S. Coast Guard or any maritime authority. Some practice questions are reproduced from public sample examinations; none are the questions used in an actual examination.
Official sources:
- COLREGs 1972 (IMO): https://www.imo.org/en/About/Conventions/Pages/COLREG.aspx
- Inland Navigation Rules, 33 CFR Part 83 (eCFR): https://www.ecfr.gov/current/title-33/chapter-I/subchapter-E/part-83
- USCG National Maritime Center sample examinations: https://www.dco.uscg.mil/nmc/Examinations/

Built for maritime students, merchant marine and deck officers, yacht captains, recreational boaters, and anyone preparing for a captain's license, a boating license or a maritime exam.

WHAT IS INCLUDED

- Flashcard System — Card-based learning tied directly to COLREG 72 paragraphs. Review each rule at your own pace and track which cards you've mastered.

- Interactive Quizzes — Test your knowledge with multiple-choice quizzes. Instant feedback, answer explanations, statistics and progress tracking help you focus on weak areas.

- Light Placement Quizzes — Put the navigation lights on the vessel silhouette yourself: masthead, side and stern lights, special signals. Hands-on questions across Rules 23–30 with hints and a light-by-light review. The fastest way to remember the nav lights of power-driven vessels, sailing vessels, tugs, trawlers, pilot boats and ships at anchor.

- Theory with Explanations — Full COLREG 72 theory broken into digestible sections, with a next-section button at the end of each one. Some light cards now explain why a vessel shows those lights.

- Sound Signals — Audio playback for all mandatory sound signals. Learn to recognize horn sequences by ear, not just by text.

- Report an Error — Found a mistake in a question? Send it from the card in a few taps.

- Tablet & Phone Support — Optimized for both phones and tablets.

- Multi-Language — Available in English, German, Russian, Spanish and French.

US NAVIGATION RULES (region set to United States, English as the app language)

- International + US Inland Rules side by side, with INTL / INLAND tags on every card
- Full text of the Inland Navigation Rules (33 CFR 83) in Theory
- Inland lights and Inland sound signal sections
- Practice exam International + Inland: 50 questions, 45 to pass
- Sample examinations based on public USCG / NMC samples (Q100, Q300, Q301, Q450) for USCG Rules of the Road exam prep (OUPV / 6-pack, Master)
- Listen to the Signal — in sound-signal questions, play the horn signal next to the question and answer by ear

WHO IS THIS FOR

- Maritime students preparing for COLREG / seamanship exams
- Captain's license candidates studying the Rules of the Road
- Professional navigators and deck officers refreshing collision avoidance rules
- Yacht skippers, sailors and boaters learning boat lights and sound signals for a boating license or boating exam
- Anyone working toward an offshore or coastal qualification

FREE & PRO

The free version includes core flashcards and quizzes supported by ads. Upgrade to Pro to remove all ads and unlock the complete theory library, the full quiz bank and sound signals content. In the US profile, Pro also unlocks the practice exam, all four sample examinations and the Inland lights, situations and rules sections; the Inland Rule 34 sound signals section is free.

Download COLREG 72 and start mastering the rules of the road today.

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Support: support@happyjigsaw.com
Maritime rules of the road & USCG exam prep: navigation lights & sound signals
Updated on
Nov 10, 2026

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
  • This app may share these data types with third parties
    Device or other IDs
  • This app may collect these data types
    Personal info, App activity and 2 others
  • Data is encrypted in transit
  • You can request that data be deleted

Ratings and reviews

3.2K reviews
Jesse
February 6, 2025
Nearly perfect, but there should be a way to do the quiz in a random order. Currently it presents questions like - fishing vessel moving head on, fishing vessel moving to the left, fishing vessel moving to the right. This makes it too easy to guess and makes it much more difficult to learn properly. A random order feature would make this perfect
11 people found this review helpful
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Andy Jarman
March 12, 2026
One of the few comprehensive guides to the colleges. The day shapes helped me understand a lot of the underlying logic that I couldn't discern from the text of the legislation alone.
2 people found this review helpful
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Happy Jigsaw
April 5, 2026
We are pleased that you enjoyed the app. If there is anything we can do for you, just let us know at support@happyjigsaw.com! Have a wonderful day!
Julia Oga
July 20, 2024
Good but must be modernised with nice illustrations !!! Sometimes contents are too heavy and it could be better to learn it with essential explanations.
1 person found this review helpful
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What’s new

Place the Lights
Vessels in light placement quizzes are now realistic renders, and the light positions match Annex I more closely: masts, sidelights and Rule 28 lights sit where they are on a real vessel.

Stability fix for a crash when opening a section.