Free interactive quiz
Ten encounters, one question each time: who keeps clear? Decide, check, and read the rule that says so.
10 questions · about 6 min · no sign-up · Updated
Every scenario is drawn from above with your vessel in purple. Assume risk of collision exists, that both vessels can see each other, and that it is open water unless the question says otherwise. The wind arrow, where shown, points the way the wind is blowing.
There is no “right of way” in the rules — one vessel keeps out of the way, the other keeps her course and speed until she must act too. The explanations use the rules' own words.
Want to learn it first? COLREGs: a repeatable method for solving any encounter.
10 questions
Question 1 of 10
Answer: Both vessels alter course to starboard and pass port to port
Rule 14 (head-on situation): 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 passes on the port side of the other. Neither vessel is stand-on; both act. If in any doubt whether it is head-on, assume it is and alter to starboard (Rule 14(c)).
COLREGs Rule 14
Answer: You — she is on your starboard side, so you keep out of her way
Rule 15 (crossing situation): 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. The usual action is an early, substantial alteration to starboard to pass astern of her (Rules 8 and 16).
COLREGs Rule 15
Answer: Keep your course and speed as the stand-on vessel, and be ready to act if she does not
She has you on her starboard side, so under Rule 15 she is the give-way vessel and you are the stand-on vessel. Rule 17 says you shall keep your course and speed — but you may take action yourself as soon as it becomes apparent she is not taking appropriate action, and you must act when collision cannot be avoided by her action alone. If you do act in a crossing situation, avoid altering to port for a vessel on your own port side (Rule 17(c)).
COLREGs Rules 15 and 17
Answer: The motor boat — any vessel overtaking another keeps out of the way
Rule 13 applies to any vessel overtaking any other, and it takes precedence over the other steering rules. A vessel is overtaking when she comes up from more than 22.5° abaft the beam of the vessel ahead — the sector in which she would see only the stern light at night. The overtaking vessel keeps out of the way until finally past and clear, whatever her type.
COLREGs Rule 13
Answer: You — the vessel with the wind on the port side keeps out of the way
Rule 12(a)(i): when each sailing vessel has the wind on a different side, the vessel which has the wind on the port side shall keep out of the way of the other. The windward side is the side opposite to that on which the mainsail is carried (Rule 12(b)) — so the boat with her boom out to starboard is on port tack and gives way.
COLREGs Rule 12(a)(i)
Answer: You — the vessel to windward keeps out of the way of the vessel to leeward
Rule 12(a)(ii): when two sailing vessels approach with risk of collision on the same tack, the windward vessel keeps clear of the leeward vessel. Check overtaking first: Rule 13 takes precedence if that is the encounter. The action must be safe for the actual traffic and conditions; bearing away is not always the answer.
COLREGs Rule 12(a)(ii)
Answer: The motor boat — a power-driven vessel keeps out of the way of a sailing vessel
Rule 18(a)(iv): a power-driven vessel underway shall keep out of the way of a sailing vessel — except where Rules 9, 10 and 13 otherwise require. Rule 15 is for two power-driven vessels and does not decide this encounter. Your sailing vessel is stand-on under Rule 17: keep course and speed, watch her, and be ready to act if she does not.
COLREGs Rule 18(a)(iv)
Answer: You — an overtaking vessel keeps out of the way, even under sail
Rule 18 opens with “except where Rules 9, 10 and 13 otherwise require”. Rule 13(a) says that notwithstanding anything in Rules 4–18, any vessel overtaking any other shall keep out of the way of the vessel being overtaken. A sailing vessel overtaking a power-driven vessel is the give-way vessel.
COLREGs Rules 13 and 18
Answer: No — a sailing vessel shall not impede a vessel that can navigate only within a narrow channel
Rule 9(b): a vessel of less than 20 metres in length or a sailing vessel shall not impede the passage of a vessel which can safely navigate only within a narrow channel or fairway. Rule 18 applies “except where Rules 9, 10 and 13 otherwise require”, so sail-over-power does not decide this one. Keep well clear, early, and cross astern of her if you cross at all.
COLREGs Rule 9(b)
Answer: You — a power-driven vessel keeps out of the way of a vessel engaged in fishing
Rule 18(a)(iii) requires a power-driven vessel underway to keep out of the way of a vessel engaged in fishing, except where Rules 9, 10 or 13 otherwise require. Fishing status means gear restricts manoeuvrability, not simply that someone is holding a rod. The two-cone day shape applies to trawling and other fishing (Rule 26).
COLREGs Rule 18(a)(iii)
The guides behind these questions — each one sourced, diagrammed and checked against the rule text.
COLREGs
Eight questions, asked in the same order every time — in sight? overtaking? what are they? which rule? who keeps clear? what must the stand-on vessel do? is there risk? what action is enough? — applied to five worked scenarios.
11 min read
COLREGs
Sail vs sail, power vs power, overtaking, head-on and crossing: what COLREG Rules 12–18 actually require of the give-way and stand-on vessel, with diagrams and a reasoning sequence you can use in the exam and at sea.
12 min read
COLREGs
What Rules 9 and 10 require of a yacht or small vessel in a narrow channel or a traffic separation scheme: keep to starboard, do not impede, cross at right angles, use the inshore zone — and what “not impede” means alongside the steering rules.
9 min read
Questions and explanations were checked against the documents below on . Scope: International COLREGs, Rules 9 and 12–18 · Vessels in sight of one another · Risk of collision exists in every scenario. Rules, buoyage and syllabuses change and can differ by jurisdiction — the official text always takes precedence.
Linking to these organisations does not imply that they endorse SailQuiz. SailQuiz is an independent study aid. It is not affiliated with, endorsed by, accredited by, or otherwise connected to the ASA, US Sailing, the RYA, the USCG, or any other certifying body, and it is not a substitute for their official training or examinations.
The Day Skipper Theory, Actually Explained course covers Collision Regulations: Basic Right of Way, Rules of the Road: Practical Scenarios and more — every answer explained, with spaced review that brings back what you miss. Free to download, no account, works offline. One full quiz and 3 Daily Challenge rounds a day on the free plan.
