Crossing, Overtaking, or Head-On?

The decision sequence

Check in order. Overtaking always wins. If neither 1 nor 2 apply and both vessels are power-driven, it is crossing.

Rule 13 — Overtaking

• →Overtaking means approaching from a direction more than 22.5° abaft the beam — roughly from the stern arc.
• →The overtaking vessel keeps clear regardless of vessel type. A sailing vessel overtaking a power-driven vessel must keep clear. Rule 13 overrides Rule 12.
• →Rule 13(b): 'when in any doubt whether she is overtaking another, she shall assume she is.' Never assume you have right-of-way if approaching from astern.
• →The 22.5° boundary is where the sternlight arc ends — if you would see only the sternlight at night, you are likely overtaking.
• →A vessel that begins as overtaking does not shed that obligation even if she alters course and later appears to be alongside — she remains the give-way vessel until clearly past and clear.

Rule 14 — Head-On Situation

• →Both vessels alter to starboard — this is symmetrical. There is no give-way or stand-on in a head-on situation.
• →Both see the other's masthead lights (two, one above the other) and both sidelights (red and green). If you see only one sidelight, it is not head-on.
• →Rule 14(c): 'when in any doubt whether such a situation exists, she shall assume it does exist and act accordingly.' Doubt resolves toward head-on.
• →Port-to-port passing: both alter starboard and pass port side to port side. The instinct to alter to port ('give them more room') creates a head-on collision.

Rule 15 — Crossing Situation

• →The vessel with the other on her starboard side is give-way — she has the other vessel in her 'danger zone' (0° to 112.5° on her starboard bow).
• →'Avoid crossing ahead' is the specific obligation. Slow down, alter course to pass astern — do not cut across her bow.
• →The stand-on vessel holds course and speed initially (Rule 17(a)(i)), may take action if give-way vessel is not acting (Rule 17(a)(ii)), and must act when collision cannot be avoided by give-way alone (Rule 17(b)).
• →Rule 17 stand-on note: a power-driven stand-on vessel shall not alter to port when the give-way vessel is on her port side — the crossing situation where this could cause the most harm.
• →Rule 15 applies only to power-driven vessels. When a sailing vessel and a power-driven vessel are crossing, Rule 18 governs — power-driven gives way to sailing.

Common exam mistakes

• ✗Applying Rule 15 in a narrow channel — Rule 9 governs channels. A crossing vessel 'shall not impede' channel traffic, which is a higher obligation than give-way.
• ✗Forgetting Rule 13 overrides. A sailing vessel overtaking a power vessel asks 'is this a sailing-versus-power situation?' The answer is no — it is an overtaking situation and Rule 13 wins.
• ✗Thinking the tug's tow changes who is overtaking. If your vessel approaches the entire tug-and-tow from more than 22.5° abaft the tug's beam, you are overtaking the tow as a unit.
• ✗Confusing Rule 14 (both alter starboard) with Rule 15 (one gives way). Rule 14 is symmetrical. Rule 15 is not.
• ✗Believing the stand-on vessel has permanent immunity. Rule 17(b) is a requirement to act. If the give-way vessel isn't moving, the stand-on vessel must eventually take action.

USCG exam questions — Rules 13, 14, 15

Drawn from the same pool used in real USCG licensing exams. Answers and explanations are shown.

1. 1. When overtaking is possible only if the vessel to be overtaken takes action to permit safe passing in a narrow channel, Rule 9(e) requires:

   • A.The overtaking vessel to wait until the channel widens before overtaking
   • B.The vessel to be overtaken to automatically give way if the overtaking vessel sounds two prolonged blasts
   • C.The overtaking vessel to indicate intent with the appropriate signal and obtain agreement before proceeding✓
   • D.The overtaking vessel to use VHF channel 16 to obtain permission from port control

   Why: Rule 9(e) establishes a two-step process: the overtaking vessel signals intent (two prolonged plus one short for starboard, or two prolonged plus two short for port), and the overtaken vessel signals agreement with one prolonged, one short, one prolonged, one short. If agreement is not obtained, the overtake shall not proceed.

2. 2. 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.

3. 3. Rule 17(c) states that a stand-on vessel taking action in accordance with Rule 17(a)(ii):

   • A.Becomes the give-way vessel for the remainder of the encounter
   • B.Shall not alter course to port for a vessel on her own port side✓
   • C.Must first reduce speed before altering course
   • D.Must sound the appropriate maneuvering signal before acting

   Why: Rule 17(c) prohibits the stand-on vessel from altering course to port for a vessel on her own port side when she decides to act under 17(a)(ii). Turning toward a give-way vessel approaching from the port bow would increase closing rate. Turning to starboard (away from the give-way vessel) is the correct action.

4. 4. 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.

5. 5. 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.

6. 6. 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.

7. 7. Under Rule 9, a vessel shall not cross a narrow channel if such crossing:

   • A.Would require more than 5 minutes to complete
   • B.Impedes the passage of a vessel which can only safely navigate within that channel✓
   • C.Takes place during periods of restricted visibility
   • D.Is made at right angles to the channel

   Why: Rule 9(d) prohibits crossing a narrow channel if doing so would impede a vessel that can only safely navigate within the channel. The crossing vessel bears the obligation to yield; the channel-bound vessel has right of way in this scenario. Time or angle of crossing are not the legal standard.

8. 8. Two power-driven vessels are meeting on reciprocal or nearly reciprocal courses such that there is a risk of collision. Each vessel shall:

   • A.The vessel on the port side shall give way; the starboard vessel shall stand on
   • B.Alter course to port so as to pass on the port side of the other
   • C.Alter course to starboard so that each passes on the port side of the other✓
   • D.Reduce speed and wait for the other vessel to take action first

   Why: Rule 14(a) requires both vessels in a head-on situation to alter course to starboard so they pass port-to-port. This is a bilateral obligation — both act simultaneously. Altering to port would increase the closing rate on the collision course and is explicitly wrong.

9. 9. Under Rule 17(a), the stand-on vessel in a crossing situation shall:

   • A.Immediately alter course to port to open the CPA
   • B.Immediately reduce speed to allow the give-way vessel more time
   • C.Maintain her course and speed✓
   • D.Sound five short blasts and then take independent action

   Why: Rule 17(a)(i) obliges the stand-on vessel to maintain course and speed. This predictability is essential — the give-way vessel plans its maneuver based on the stand-on vessel continuing unchanged. Unpredictable early action by the stand-on vessel can negate the give-way vessel's avoidance.

10. 10. You are the stand-on vessel in a crossing situation. The give-way vessel appears to be taking no action. You sound five or more short blasts. What are you signaling under Rule 34(d)?

    • A.That you are altering course to starboard
    • B.That you are operating astern propulsion
    • C.That you are in doubt whether sufficient action is being taken to avoid collision✓
    • D.That you are engaging in restricted maneuverability

    Why: Five or more short and rapid blasts is the doubt or danger signal of Rule 34(d). As the stand-on vessel, you use this when in doubt that the give-way vessel is taking sufficient action. The signal can be supplemented by at least five flashes. It does not authorize you to take any particular action — it is a warning, not a maneuver signal.

Frequently asked questions

Which rule takes priority — overtaking or crossing?

Overtaking (Rule 13) always takes priority. Rule 13(b) states explicitly that the overtaking vessel shall keep out of the way regardless of 'anything contained in the Rules of Part B, Sections I and II' — which includes Rules 14 and 15. If any doubt exists about whether you are overtaking, assume you are.

What makes a situation 'head-on' under COLREGS?

Rule 14 applies when two power-driven vessels are meeting on reciprocal or nearly reciprocal courses. The tell: you can see both masthead lights and both sidelights of the other vessel. Rule 14(c) reinforces: when in any doubt as to whether a head-on situation exists, assume it does and alter course to starboard.

In a crossing situation, does the stand-on vessel have to hold course?

Yes, initially. Rule 17(a)(i) requires the stand-on vessel to keep her course and speed. If the give-way vessel is not taking sufficient action, the stand-on vessel may act under Rule 17(a)(ii). Once collision cannot be avoided by the give-way vessel alone, Rule 17(b) requires the stand-on vessel to take action.

Does Rule 15 (crossing) apply in a narrow channel?

No. Rule 9 governs narrow channels and overrides Rule 15. A vessel crossing a narrow channel shall not impede vessels that can only navigate within the channel. The 'shall not impede' obligation is higher than give-way — it means avoid the situation entirely, not just yield when you are already in the way.

If a sailing vessel is overtaking a power-driven vessel, who gives way?

The sailing vessel gives way. Rule 13 overrides Rule 12 (sailing vessel pecking order). The overtaking vessel must keep clear regardless of vessel type. If a sailing vessel approaches from more than 22.5° abaft the beam of any vessel ahead, it is the overtaking vessel and bears the obligation.

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