COLREGS Rule 11 — Application

Rule Text

What it means on the water

• →Section II (Rules 11–18) applies ONLY to vessels in sight of one another — they must be able to observe each other visually.
• →The substantive rules gated by Rule 11 are: Rule 12 (sailing vessels), Rule 13 (overtaking), Rule 14 (head-on), Rule 15 (crossing), Rule 16 (give-way action), Rule 17 (stand-on action), and Rule 18 (responsibilities between vessels).
• →'In sight of one another' means observed visually — a radar-only contact does NOT satisfy Rule 11, so the give-way/stand-on framework does not apply on radar alone.
• →When vessels are NOT in sight of each other (fog, etc.), Rule 19 in Section III governs instead — there is no stand-on or give-way vessel under Rule 19.
• →Contrast with Rule 4: Section I (Rules 5–10) applies in any condition of visibility; Section II applies only when vessels are in sight of each other.

Common exam mistakes

• ✗Applying the crossing or head-on rules to a radar-only contact in fog — Rule 11 requires vessels to be in sight of one another before Rules 12–18 apply.
• ✗Confusing Section II (vessels in sight) with Section I (any condition of visibility) — Rule 11 and Rule 4 set different preconditions.
• ✗Thinking the give-way/stand-on hierarchy still applies in restricted visibility — once vessels are out of sight, Rule 19 governs, not Rules 12–18.

USCG exam questions — Rule 11

These questions are drawn from the same pool used in real USCG licensing exams. Correct answers and explanations are shown.

1. 1. Two sailing vessels are approaching one another so as to involve risk of collision. Vessel A has the wind on her port side. Vessel B has the wind on her starboard side. Which vessel is the give-way vessel?

   • A.Vessel A, because she has the wind on the port side✓
   • B.Vessel B, because she has the wind on the starboard side
   • C.The vessel that is more close-hauled
   • D.The vessel to leeward

   Why: Rule 12(a)(i) states that when each sailing vessel has the wind on a different side, the vessel with the wind on the port side shall keep out of the way. Vessel A has the wind on port; she gives way. The close-hauled state and leeward position are irrelevant to this specific sub-rule.

2. 2. Under Rule 13, a vessel is overtaking another when she is approaching from a direction more than how many degrees abaft the beam of the vessel being overtaken?

   • A.30 degrees abaft the beam
   • B.45 degrees abaft the beam
   • C.22.5 degrees abaft the beam✓
   • D.60 degrees abaft the beam

   Why: Rule 13(b) defines the overtaking sector as more than 22.5 degrees abaft the beam — the same arc covered by the stern light. If you can see only the stern light of the vessel ahead, you are in the overtaking sector and must keep clear regardless of what other rules might otherwise apply.

3. 3. Under Rule 14(b), a head-on situation shall be deemed to exist when a vessel sees another vessel ahead and:

   • A.The other vessel's masthead lights are in line and her range lights can be seen
   • B.At night, she can see the masthead lights of the other vessel in a line or nearly in a line, or both sidelights✓
   • C.The bearing to the other vessel does not change over a 3-minute period
   • D.Both vessels are on courses within 10 degrees of each other

   Why: Rule 14(b) specifies the visual indicators of a head-on situation at night: masthead lights in line (or nearly in line) and/or both sidelights visible. This is the practical way mariners identify the head-on meeting without requiring precise course comparison.

4. 4. Rule 15 adds that, where possible, the give-way vessel in a crossing situation shall avoid:

   • A.Reducing speed, which could confuse the stand-on vessel
   • B.Crossing ahead of the other vessel✓
   • C.Altering course to starboard when the other vessel is on her starboard side
   • D.Sounding any signal that could be misinterpreted

   Why: Rule 15 states that the give-way vessel shall, if the circumstances of the case admit, avoid crossing ahead of the other vessel. Passing astern is the preferred maneuver; crossing ahead risks collision if the give-way vessel underestimates the closing speed or the stand-on vessel maintains speed.

5. 5. Rule 17(a)(ii) permits the stand-on vessel to take action when:

   • A.The CPA drops below 1 nautical mile
   • B.It becomes apparent to her that the give-way vessel is not taking appropriate action✓
   • C.The give-way vessel sounds the doubt signal of five short blasts
   • D.The stand-on vessel's officer of the watch judges the situation to be unsafe

   Why: Rule 17(a)(ii) allows the stand-on vessel to act when it becomes apparent the give-way vessel is NOT taking appropriate action. This is a permission, not a requirement at that stage. The stand-on vessel should not act prematurely but should not wait until collision is inevitable.

6. 6. Under Rule 13, any vessel overtaking any other vessel shall:

   • A.Keep out of the way of the vessel being overtaken✓
   • B.Sound one prolonged blast to signal her intention to overtake
   • C.Proceed at a speed sufficient to complete the overtaking in minimum time
   • D.Overtake only on the starboard side of the vessel ahead

   Why: Rule 13(a) places an absolute duty on the overtaking vessel to keep out of the way of the vessel being overtaken, regardless of any other rule that might otherwise apply. Rule 13 overrides the head-on and crossing rules — once in the overtaking sector, Rule 13 governs.

7. 7. Which body has the authority to issue special rules for roadsteads, harbors, rivers, lakes, or inland waterways under COLREGS Rule 1(b)?

   • A.The appropriate authority of each country✓
   • B.The International Maritime Organization (IMO) only
   • C.The port captain or harbormaster of each port
   • D.The United Nations Commission on Maritime Law

   Why: COLREGS Rule 1(b) specifically grants each contracting government (the appropriate national authority) the power to make special rules for inland waters, harbors, and roadsteads, provided those rules conform as closely as possible to the COLREGS.

8. 8. A vessel departs from the rules of the road to avoid an imminent collision. Under Rule 2(b), this action is:

   • A.Permitted, as the rules allow departure from their requirements when necessary to avoid immediate danger✓
   • B.Prohibited, because the rules must be followed absolutely in all circumstances
   • C.Permitted only if approved by the vessel's flag state authority in advance
   • D.Permitted only for vessels of more than 20 meters in length

   Why: Rule 2(b) explicitly states that in construing the rules, due regard shall be had to special circumstances that may make departure from the rules necessary to avoid immediate danger — codifying the 'last resort' principle of good seamanship.

Frequently asked questions

What does Rule 11 of the COLREGS cover?

Rule 11 is the application clause for Section II of the Steering and Sailing Rules. It states that the rules in this Section apply to vessels in sight of one another. This makes Rules 12 through 18 — sailing vessels, overtaking, head-on, crossing, give-way action, stand-on action, and the responsibility hierarchy — applicable only when vessels can observe each other visually.

Do the crossing and head-on rules apply if I only see another vessel on radar?

No. Rule 11 requires that vessels be in sight of one another for Rules 12 through 18 to apply, and 'in sight' means observed visually. If the only contact is by radar, such as in fog, the give-way and stand-on framework does not apply — Rule 19 in Section III governs the conduct of vessels in restricted visibility instead.

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