COLREG Rules — International Regulations for Preventing Collisions at Sea
Study all 41 COLREG rules with attributed source text, explanations and practice questions. Check the conditions and exceptions in each rule.
COLREG, in one paragraph
COLREG is the Convention on the International Regulations for Preventing Collisions at Sea, 1972. It was adopted on 20 October 1972 and entered into force on 15 July 1977. As amended, it contains 41 rules in six Parts, A–F, and four Annexes. Rule 1 defines its scope: all vessels on the high seas and in connected waters navigable by seagoing vessels.
A
Part A — General
3B
Part B — Steering & Sailing Rules
16Section I.Conduct in any condition of visibility
Section II.Conduct in sight of one another
Section III.Conduct in restricted visibility
C
Part C — Lights & Shapes
12- 20Application (Lights)
- 21Definitions (Lights)
- 22Visibility of Lights
- 23Power-driven Vessels Underway
- 24Towing and Pushing
- 25Sailing Vessels Underway and Vessels Under Oars
- 26Fishing Vessels
- 27Vessels Not Under Command or Restricted in Ability to Manoeuvre
- 28Vessels Constrained by Their Draught
- 29Pilot Vessels
- 30Anchored Vessels and Vessels Aground
- 31Seaplanes
D
Part D — Sound & Light Signals
6E
Part E — Exemptions
1F
Part F — Verification of Compliance
3What are the COLREGs?
(a) These Rules shall apply to all vessels upon the high seas and in all waters connected therewith navigable by seagoing vessels.
A — General (1–3): Application, responsibility, definitions; B — Steering & Sailing (4–19): Conduct in any visibility, in sight of one another, and in restricted visibility; C — Lights & Shapes (20–31): Navigation lights and day shapes by vessel type; D — Sound & Light Signals (32–37): Whistle, bell, gong and distress signals; E — Exemptions (38): Specified technical exemptions for eligible older vessels; F — Verification of compliance (39–41): Contracting Parties and the IMO audit scheme.
Study all 41 COLREG rules with attributed source text, explanations and practice questions. Check the conditions and exceptions in each rule.
COLREG structure at a glance
| Part | Rules | What it covers |
|---|---|---|
| A — General | 1–3 | Application, responsibility, definitions |
| B — Steering & Sailing | 4–19 | Conduct in any visibility, in sight of one another, and in restricted visibility |
| C — Lights & Shapes | 20–31 | Navigation lights and day shapes by vessel type |
| D — Sound & Light Signals | 32–37 | Whistle, bell, gong and distress signals |
| E — Exemptions | 38 | Specified technical exemptions for eligible older vessels |
| F — Verification of compliance | 39–41 | Contracting Parties and the IMO audit scheme |
Selected COLREG topics
- Rule 13 — OvertakingFor vessels in sight, every overtaking vessel keeps clear until finally past and clear. Rule 13 takes precedence over Part B Sections I and II; it does not override the other Parts of COLREG.
- Rule 14 — Head-on situationRules in this section apply to vessels in sight of one another. (a) When two power-driven vessels are meeting on reciprocal or nearly reciprocal courses so as to involve risk of collision each shall alter her course to starboard so that each shall pass on the port side of the other.
- Rule 15 — Crossing situationRules in this section apply to vessels in sight of one another. When two power-driven vessels are crossing so as to involve risk of collision, the vessel which has the other on her own starboard side shall keep out of the way and shall, if the circumstances of the case admit, avoid crossing ahead of the other vessel.
- Rule 18 — Responsibilities between vesselsRule 18 does not rank not-under-command above restricted-in-ability-to-manoeuvre vessels. Its duties are subject to Rules 9, 10 and 13; they do not create an absolute right of way.
- Rule 19 — Conduct in restricted visibility(a) This Rule applies to vessels not in sight of one another when navigating in or near an area of restricted visibility.
- Lights & shapes (Rules 20–31)Visual examples of navigation lights and day shapes.
Frequently asked questions
What does COLREG stand for?
COLREG is shorthand for the Convention on the International Regulations for Preventing Collisions at Sea, 1972. You'll also see COLREGS (the rules themselves), IRPCS (the British abbreviation), RIPA (Spain), RIPAM (France) and KVR (Germany) — all refer to the same IMO text.
Are the COLREGs the same in every country?
(b) Nothing in these Rules shall interfere with the operation of special rules made by an appropriate authority for roadsteads, harbors, rivers, lakes or inland waterways connected with the high seas and navigable by seagoing vessels. Such special rules shall conform as closely as possible to these Rules.
When does Rule 19 apply instead of Rules 11–18?
Rules 4–10 apply in any visibility. Rules 11–18 apply to vessels in sight of one another; Rule 19 applies to vessels not in sight when navigating in or near an area of restricted visibility.
Do COLREGs apply to small boats and jet skis?
(a) These Rules shall apply to all vessels upon the high seas and in all waters connected therewith navigable by seagoing vessels. Small craft are included. Requirements depend on vessel type, length and operating condition; some light and sound provisions have specific small-vessel alternatives or exemptions.
When were the COLREGs last updated?
Checked against the IMO 2026 edition: the latest amendments are Resolution A.1085(28), adopted on 4 December 2013 and effective from 1 January 2016. They added Part F, Rules 39–41, on verification of compliance and the IMO audit scheme.
How many rules are there in the COLREGs?
There are 41 rules in six Parts, A–F. Four Annexes cover the positioning and technical details of lights and shapes; additional signals for fishing vessels fishing in close proximity; sound-signal appliances; and distress signals.
What are the Parts of the COLREGs?
A — General (1–3): Application, responsibility, definitions; B — Steering & Sailing (4–19): Conduct in any visibility, in sight of one another, and in restricted visibility; C — Lights & Shapes (20–31): Navigation lights and day shapes by vessel type; D — Sound & Light Signals (32–37): Whistle, bell, gong and distress signals; E — Exemptions (38): Specified technical exemptions for eligible older vessels; F — Verification of compliance (39–41): Contracting Parties and the IMO audit scheme.
What does COLREG stand for (full form)?
COLREG is short for the Convention on the International Regulations for Preventing Collisions at Sea, 1972 — that full form is the official name of the convention. In everyday use COLREG refers to the convention and COLREGS to the 41 rules it contains, but the two abbreviations point at exactly the same IMO text, adopted on 20 October 1972 and in force since 15 July 1977.
What is the difference between COLREG, COLREGS and IRPCS?
There is no difference in substance: they are three names for one document. COLREG abbreviates the convention's title, COLREGS is the plural people use for the rules themselves, and IRPCS — International Regulations for Preventing Collisions at Sea — is the abbreviation used in British training and exams. RIPA in Spain, RIPAM in France and KVR in Germany are the same convention again under its local name, so Rule 15 means the same thing in every one of them.
Is there a free PDF of COLREG rules 1–41?
Use the printable study summary and choose “Save as PDF” in your browser’s print dialog. It summarizes all 41 rules; it is not the complete text of the Convention.
What is COLREG 72?
“COLREG 72”, also written COLREG 1972 or COLREGs 72, is the convention with its year attached — the Convention on the International Regulations for Preventing Collisions at Sea, 1972, adopted on 20 October 1972 and in force since 15 July 1977. The 72 distinguishes it from the 1960 collision regulations it replaced. It is not a separate ruleset: it is the same 41 rules in Parts A–F that apply today, as amended.