COLREGS (International Rules) Exam Prep

COLREGS 1972 — The International Rules of the Road

The Convention on the International Regulations for Preventing Collisions at Sea, 1972 (COLREGS 72, as amended) is the single most universally examined body of maritime regulation. Adopted by the IMO in 1972 and entering into force in 1977, COLREGS governs the conduct of every vessel on the high seas and in all waters connected therewith navigable by seagoing vessels. Every bridge-watch officer on every commercial ship — USCG, MCA, Transport Canada, AMSA, MNZ, DG-IN, MARINA, MI-IRI, Liberia, Singapore, Panama, Bahamas — is examined on COLREGS.

COLREGS applies to seafarers on fishing vessels, yachts, warships, and merchant ships. If your licence puts you on a bridge, you will be tested on COLREGS.

Structure of the convention

COLREGS is organised into Part A (General, Rules 1–3), Part B (Steering and Sailing Rules, Rules 4–19), Part C (Lights and Shapes, Rules 20–31), Part D (Sound and Light Signals, Rules 32–37), Part E (Exemptions, Rule 38), Part F (Verification of compliance, Rule 39–41), and Four Annexes (I–IV) covering positioning of lights, additional signals for fishing vessels, technical details of sound signals, and distress signals.

The Steering and Sailing Rules are further divided into Section I (Any condition of visibility, Rules 4–10), Section II (Vessels in sight of one another, Rules 11–18), and Section III (Restricted visibility, Rule 19). The visibility distinction is load-bearing on nearly every written exam.

Which national exams test this

Every national CoC includes COLREGS as a standalone subject. Specifically:

• USCG — Tests COLREGS plus the Inland Navigation Rules (enacted under 33 USC 2001 and 33 CFR 83), with many identical rules but several differences (lights for Western Rivers, signal-by-lamp on the Great Lakes).
• UK MCA — SQA Navigation papers and the MCA Oral; COLREGS is probed scenario-style throughout the oral.
• Transport Canada — Navigation Safety Level 1 paper, plus the *Collision Regulations* (Canadian Modifications) for narrow channels on the St Lawrence Seaway and Great Lakes.
• AMSA — Written Navigation paper and oral, tested against Marine Order 30.
• Maritime NZ — *Maritime Rules Part 22* is the NZ enactment of COLREGS.
• DG-IN — Function 1 written paper and Function 1 viva voce.
• MARINA — MARINA Licensure Examination Navigation paper and oral.
• MI-IRI — MI-319 Section 1, with a 90 percent pass threshold (highest in the industry).

Exam question styles across authorities

USCG COLREGS questions are multiple-choice with four alternatives, often keyed to specific rule numbers. MCA oral COLREGS questions are Socratic scenarios — "You're the OOW inbound to Felixstowe, crossing a fishing vessel fine to port, what do you do?" — requiring reasoning from Rules 15 and 17 simultaneously. DG-IN Function 1 oral is hybrid — the Nautical Surveyor may require the candidate to quote a rule verbatim and then apply it. AMSA and MNZ emphasize TSS compliance under Rule 10. MARINA oral assessors use SMCP bridge-pilot exchanges as the vehicle for COLREGS testing. MI-IRI written exams under MI-319 require the 90 percent pass bar — effectively near-perfection.

Landmark rules / articles to memorize

• Rule 2 (Responsibility) — the "good-seamanship clause"; a defence-and-sword rule in incident inquiries.
• Rule 5 (Look-out) — proper look-out by sight and hearing and all available means.
• Rule 6 (Safe Speed) — includes the radar-performance factors in Rule 6(b).
• Rule 7 (Risk of Collision) — "if the compass bearing of an approaching vessel does not appreciably change".
• Rule 8 (Action to Avoid Collision) — positive, ample, in plenty of time.
• Rule 9 (Narrow Channels) — shall not impede, Rule 9(d) overtaking protocol.
• Rule 10 (TSS) — the most-litigated rule; reviewed again in Rule 10(j) for fishing vessels.
• Rules 11–18 (Conduct in sight) — power-driven head-on, crossing, overtaking; stand-on vs give-way.
• Rule 19 (Restricted Visibility) — the most commonly failed rule globally. Section III applies *only* in or near an area of restricted visibility; action under Rule 19(d) is key.
• Rule 15 vs Rule 19 confusion is the #1 oral-examination failure mode.

Common pitfalls

The most persistent COLREGS error is applying Section II rules in restricted visibility. Section III (Rule 19) governs when vessels are *not in sight of one another* in or near restricted visibility. A radar contact is not a sight contact. Other frequent pitfalls: misidentifying a vessel not under command versus a vessel restricted in ability to manoeuvre (Rule 3 definitions), forgetting that Rule 17(a)(ii) *permits* the stand-on vessel to act when the give-way vessel is not taking appropriate action, and misplacing the boundary between a close-quarters situation and risk of collision.

Study strategy using MMCE.app

MMCE.app ships 593 COLREGS questions (304 authored from scratch, peer-reviewed against the *COLREGS 1972 consolidated text with 2019 amendments*). Our adaptive engine pushes the Rules of the Road theta to 90-percent mastery on every credential, matching the strictest national pass threshold (MI-319). We ship spaced-repetition flashcards keyed to each rule number, and the Claude tutor cites the exact rule and subclause on every missed question.

How the convention is updated

COLREGS is amended through the IMO Maritime Safety Committee (MSC) under a tacit-acceptance procedure (Article VI). The last major package was the 2019 amendments introducing updated definitions for wing-in-ground craft and technical revisions to Annex I. The MSC meets twice yearly; amendments typically enter force 18 months after adoption. Flag states are required to incorporate amendments into national law — UK through a Merchant Shipping Notice, Canada through amendment of C.R.C. c. 1416, USCG through revisions to 33 CFR 83.