Free COLREGs trainer
Learn the collision regulations, rule by rule.
Every rule from the look-out to the distress signals, with moving scenes, navigation light flashcards, the sound signals to listen to, and a quiz. No account needed.
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The lessons
The International Regulations for Preventing Collisions at Sea, in bite-sized lessons. Tick each one off as you learn it.
Part A: General
0 / 1 learnedApplication, responsibility, and definitions that apply to all the rules.
Part B: Steering and Sailing Rules
0 / 16 learnedHow vessels must behave when navigating, in any visibility, when in sight of one another, and in restricted visibility.
- Rule 4Application of Section IRules 4 to 10 apply in any condition of visibility: in clear weather and in fog alike.
- Rule 5Look-outMaintain a proper look-out by sight, hearing and all available means.
- Rule 6Safe SpeedProceed at a speed allowing proper and effective action to avoid collision.
- Rule 7Risk of CollisionUse all available means to determine if risk of collision exists; if in doubt, it does.
- Rule 8Action to Avoid CollisionAction shall be positive, made in ample time, and with due regard to good seamanship.
- Rule 9Narrow ChannelsKeep to the outer limit of the channel on her starboard side.
- Rule 10Traffic Separation SchemesProceed in the appropriate traffic lane; cross at right angles where required.
- Rule 11Application of Section IIRules 11 to 18 apply only to vessels in sight of one another.
- Rule 12Sailing VesselsWind on different sides → port-tack gives way; same side → windward gives way.
- Rule 13OvertakingAny vessel overtaking shall keep out of the way of the vessel being overtaken.
- Rule 14Head-on SituationEach shall alter course to starboard so as to pass on the port side of the other.
- Rule 15Crossing SituationThe vessel which has the other on her starboard side shall keep out of the way.
- Rule 16Action by Give-way VesselTake early and substantial action to keep well clear.
- Rule 17Action by Stand-on VesselKeep course and speed; act if give-way vessel does not.
- Rule 18Responsibilities Between VesselsPower-driven keeps clear of NUC, RAM, fishing and sailing; sailing of NUC, RAM and fishing; fishing of NUC and RAM. All but NUC and RAM avoid impeding a CBD.
- Rule 19Conduct in Restricted VisibilitySafe speed in RV; on radar alone, avoid turning to port for a vessel forward of the beam (unless overtaking her) or towards one abeam or abaft.
Part C: Lights and Shapes
0 / 12 learnedWhat lights and dayshapes vessels must exhibit, when, and what they mean.
- Rule 20Application of Part CLights from sunset to sunrise and in restricted visibility; shapes by day; in all weathers.
- Rule 21DefinitionsMasthead, sidelights, sternlight, towing light, all-round, flashing.
- Rule 22Visibility of LightsMinimum ranges depending on vessel length.
- Rule 23Power-driven Vessels UnderwayMasthead, sidelights, sternlight; second masthead if ≥ 50 m.
- Rule 24Towing and PushingAdditional masthead lights and towing light; tow length matters.
- Rule 25Sailing Vessels and Vessels Under OarsSidelights and sternlight; optional red-over-green at masthead.
- Rule 26Fishing VesselsTrawling: green-over-white; other fishing: red-over-white.
- Rule 27Vessels NUC or RAMNUC: two reds. RAM: red-white-red, plus appropriate shapes.
- Rule 28Vessels Constrained by DraughtThree all-round red lights in a vertical line; cylinder by day.
- Rule 29Pilot VesselsWhite-over-red all-round lights when on pilotage duty.
- Rule 30Anchored Vessels and Vessels AgroundAnchored: all-round white(s); aground: anchor lights + two reds.
- Rule 31SeaplanesConform as closely as possible to the lights/shapes required.
Part D: Sound and Light Signals
0 / 6 learnedWhistle, bell and gong signals used for manoeuvring, warning, and in restricted visibility.
- Rule 32DefinitionsShort blast (~1 s) and prolonged blast (4–6 s).
- Rule 33Equipment for Sound SignalsA whistle from 12 m, a bell as well from 20 m, and a gong as well from 100 m.
- Rule 34Manoeuvring and Warning SignalsOne short = stbd, two = port, three = astern; five+ = doubt.
- Rule 35Sound Signals in Restricted VisibilityPDV making way: one prolonged blast at intervals of not more than 2 min; many variants by vessel state.
- Rule 36Signals to Attract AttentionLight or sound signals that cannot be mistaken for any other signal.
- Rule 37Distress SignalsDistress signals are listed in Annex IV.
Part E: Exemptions
0 / 1 learnedTransitional exemptions for vessels constructed before the Rules entered into force.
Annexes
0 / 4 learnedTechnical annexes to the Regulations.
- Annex IPositioning & Technical Details of Lights and ShapesWhere lights and shapes must be placed, their dimensions, colours, intensity and sectors.
- Annex IIAdditional Signals for Fishing Vessels Fishing in Close ProximityExtra lights for trawlers and purse seiners when working near one another.
- Annex IIITechnical Details of Sound Signal AppliancesWhistle frequencies and ranges, bell and gong specifications.
- Annex IVDistress SignalsSignals indicating distress and need of assistance.
Download the rules
- These are reference copies. The legal text is the one published by your national maritime authority, so check it before relying on any detail.
- In the US Coast Guard handbook, read the International column. The Inland column applies only on US inland waters.
- The Canadian copy is not an official version, and it carries Canada’s own modifications to the rules.
- Australia applies the international rules through Marine Order 30, which points to the rules but does not print them.
- Your state, region or harbour can make its own rules for its waters, such as speed limits, local zones and port by-laws. Check the rules for the waters you are in.
Free copies to download
- US Coast Guard Navigation Rules and Regulations Handbook US Coast Guard Navigation Center · PDF, 7.5 MB · Corrected 8 August 2024
The full international rules with all four Annexes, US Coast Guard edition, free to print. Read the International column; the Inland column is for US inland waters only.
Source: US Coast Guard Navigation Center, navcen.uscg.gov, Navigation Rules and Regulations Handbook, corrected 8 August 2024. A US Government work, not subject to copyright. Shimbiri is not affiliated with the US Coast Guard. Licence: A work of the US Government: copyright protection is not available for it (17 U.S.C. 105). The publisher’s copy.
- Canada Collision Regulations Government of Canada, Justice Laws Website · PDF, 0.7 MB · Consolidation current to 21 September 2026
The same international rules with all four Annexes, in English and French, with Canada’s own changes marked in. Current to 21 September 2026.
Source: Collision Regulations, C.R.C., c. 1416, Justice Laws Website, laws-lois.justice.gc.ca, consolidation current to 21 September 2026. Reproduced under the Reproduction of Federal Law Order. This is not an official version. Licence: Reproduction of Federal Law Order (SI/97-5): anyone may reproduce federal enactments without charge or permission, provided the copy is accurate and is not represented as an official version. The publisher’s copy.
- Australia: Marine Order 30 (Prevention of collisions) 2016 Federal Register of Legislation · PDF, 0.9 MB, 5 pages · As made, registered 19 July 2016, in force 1 August 2016
The 5-page Australian order that makes the international rules law in Australian waters. It points to the rules; it does not print them.
Sourced from the Federal Register of Legislation at 10 October 2026. For the latest information on Australian Government law please go to https://www.legislation.gov.au. Licensed under CC BY 4.0. Licence: Creative Commons Attribution 4.0 International (CC BY 4.0). The publisher’s copy.
On the publishers’ own sites
- UK: MSN 1781 (M+F) Amendment 3 Maritime and Coastguard Agency, gov.uk · Web page · Published 21 November 2023
How the UK applies the international rules, including to jet skis and other watercraft. It does not print the rules.
Contains public sector information licensed under the Open Government Licence v3.0.
- New Zealand: Maritime Rules Part 22, Collision Prevention Maritime New Zealand · Web page, with the PDF · Consolidation 31 March 2021
New Zealand’s version of the rules, renumbered 22.1 to 22.40, for boats in NZ waters.
Maritime NZ is the source and copyright holder.
- IMO: the COLREG Convention International Maritime Organization · Web page
The body that writes the rules. The official consolidated book is sold through IMO and its distributors.
A training aid, not the official text. The COLREGs are an IMO convention, and your national authority publishes the version that applies in its waters. Check the rules themselves before you rely on them at sea. Download the rules.