Pass Rules of the Road at 90% the first time — adaptive COLREGS practice questions with AI explanations

If you are sitting for any deck-side license on any flag state, COLREGS is the one module you cannot afford to guess on. The International Regulations for Preventing Collisions at Sea, 1972 (as amended) — the 38 Rules plus Annexes I through IV — is treated as safety-critical by every maritime authority, and that is why the United States Coast Guard requires a 90% pass mark on the Rules of the Road exam while every other MMC module passes at 70%.

On MMCE.app, COLREGS practice questions are the heart of deck-track preparation. Our question bank covers every rule and every annex, scored against a 90% threshold, and our adaptive engine learns exactly which rules you are weakest on and drills them until your theta for the module climbs above the pass line.

What the exam actually tests

The USCG Rules of the Road exam is 50 questions, 90 minutes, and you must answer 45 of 50 correctly to pass. MCA, Transport Canada, AMSA, Maritime NZ, DG Shipping India, MARINA, and RMI each wrap Rules of the Road into their own deck-officer knowledge exams, sometimes as a standalone paper and sometimes folded into a larger navigation safety exam. Time pressure is real: most candidates report they spend 60-70% of their preparation time on COLREGS alone because a single wrong answer can pull you below 90%.

The questions are heavily scenario-based. You will see a vessel-encounter diagram, a lights-at-night description, or a restricted-visibility radar plot, and you will be asked which rule applies, what action is required, and which vessel is the give-way or stand-on.

Which credentials test this

• USCG — Third Mate, Second Mate, Chief Mate, Master, OUPV, Master 100/200/500/1600 GRT, Master Near Coastal, Mate of Towing, Master of Towing. Separate International and Inland Rules exams.
• MCA (UK) — OOW (Deck) Unlimited, Chief Mate, Master Unlimited. Navigation Safety written paper.
• Transport Canada — Watchkeeping Mate, Chief Mate, Master Mariner. Navigation Safety Level 1/2/3.
• AMSA (Australia) — Master <500 GT, Deck Watchkeeper, Master Unlimited.
• Maritime NZ — Master 200, Master 500, Deck Watchkeeper.
• DG Shipping India — Second Mate FG, Chief Mate FG, Master FG. COLREGS is a dedicated paper.
• MARINA (Philippines) — Officer in Charge of a Navigational Watch (OICNW).
• RMI (Marshall Islands) — all deck endorsements issued on a USCG base require the same Rules of the Road knowledge.

Core subject-matter breakdown

• Rule 5 — Lookout. Proper lookout by sight, hearing, and all available means. Candidates miss the "all available means" language and forget that radar and AIS are part of the lookout.
• Rule 6 — Safe speed. The six factors for all vessels plus six additional for radar-equipped vessels. Frequently tested in restricted-visibility scenarios.
• Rules 13, 14, 15 — Overtaking, head-on, crossing. The give-way/stand-on framework. Rule 13 overrides 14 and 15: if you are overtaking you remain the give-way vessel until finally past and clear.
• Rule 19 — Restricted visibility. No give-way/stand-on — both vessels are required to take action. Turn-away rules for vessels forward of the beam are the single most-missed scenario.
• Lights and shapes (Rules 20-31). Masthead, sidelight, sternlight, towing lights, NUC, RAM, CBD, fishing, pilot, anchor. Annex I gives arc-of-visibility and positioning.
• Sound and light signals (Rules 32-37). Short blast, prolonged blast, maneuvering signals, restricted visibility signals, distress signals per Annex IV.
• Annexes. Annex I (lights positioning), II (fishing vessels in close proximity), III (sound appliances), IV (distress signals).

Common pitfalls & traps

• Confusing stand-on and give-way in crossing situations when a small angle change makes it look like head-on.
• Forgetting that Rule 19 has no stand-on vessel — both take action.
• Misidentifying a RAM (Restricted in Ability to Maneuver) light configuration versus NUC (Not Under Command).
• Applying Inland Rules to an International scenario and vice versa. The USCG tests them separately and the differences (wake damage, special-circumstance signals) trip up candidates.
• Treating safe speed as a fixed number rather than a judgment governed by Rule 6 factors.

How MMCE.app prepares you

Our adaptive engine uses a 3-parameter logistic IRT model to estimate your theta for each COLREGS sub-module (steering/sailing, lights/shapes, sounds, restricted visibility, annexes). Every question you miss is queued into a SuperMemo-2 spaced-repetition deck so you see it again on the day you are most likely to forget it.

The AI tutor — powered by Claude — does not just tell you the right answer. It cites the exact rule number and paragraph, walks you through the logic of the encounter, and lets you ask follow-up questions in plain English. Full-length Rules of the Road practice tests mimic the 50-question USCG format so you know your readiness score is calibrated to the real 90% threshold.

Related credentials on MMCE.app

COLREGS is tested on every deck credential in our catalog: Third Mate, Second Mate, Chief Mate, Master (all tonnages), OUPV, Master Near Coastal, Mate of Towing, Master of Towing, Master 100/200/500/1600, and the Able Seaman endorsement. If you are on the deck track, Rules of the Road is the module you will see every time you open the app.