COLREGS Rule 13 — Overtaking

Rule Text

What it means on the water

• →Overtaking: approaching from more than 22.5° abaft the beam of the vessel ahead.
• →At night: if you can see only the sternlight (no sidelights), you are overtaking.
• →The overtaking vessel must ALWAYS keep out of the way — even if the overtaking vessel is a sailing vessel or NUC.
• →Any doubt about whether the situation is overtaking = assume it is overtaking.
• →Rule 13 overrides Rule 12 (sailing vessels) and other steering/sailing rules when an overtaking situation exists.

Common exam mistakes

• ✗Thinking a sailing vessel overtaking a power vessel has right of way — Rule 13 overrides Rule 12.
• ✗Using 45° rather than 22.5° as the boundary angle — it is 22.5° abaft the beam.
• ✗Forgetting the doubt resolution: any doubt = assume overtaking.

USCG exam questions — Rule 13

These questions are drawn from the same pool used in real USCG licensing exams. Correct 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. Two sailing vessels both have the wind on the same side. Under Rule 12, which is the give-way vessel?

   • A.The vessel to windward shall keep out of the way of the vessel to leeward✓
   • B.The vessel to leeward shall keep out of the way of the vessel to windward
   • C.The vessel on the starboard tack shall keep out of the way
   • D.The vessel that is making greater speed through the water

   Why: Rule 12(a)(ii) states that when both sailing vessels have the wind on the same side, the windward vessel keeps out of the way of the leeward vessel. The leeward vessel has less sea room to maneuver and the windward vessel can readily bear away.

3. 3. A vessel that is overtaking another begins to draw abeam and eventually moves ahead. At what point does the overtaking obligation end under Rule 13?

   • A.When the overtaking vessel is clearly past and well clear of the overtaken vessel✓
   • B.When the overtaken vessel can see the overtaking vessel's sidelights
   • C.When the overtaking vessel sounds two short blasts to indicate she is clear
   • D.As soon as the overtaking vessel crosses ahead of the overtaken vessel's bow

   Why: Rule 13(d) states that the overtaking vessel shall keep clear until she is finally past and clear. The obligation persists through the entire overtaking maneuver — there is no intermediate point where the give-way duty switches. The 'past and clear' standard is intentionally high to prevent premature assumption that the maneuver is complete.

4. 4. Rule 14(c) states that if a vessel is in any doubt as to whether a head-on situation exists, she shall:

   • A.Stand on and wait for the other vessel to take action
   • B.Sound the doubt signal of five short blasts
   • C.Assume a head-on situation exists and act accordingly✓
   • D.Contact the other vessel on VHF to clarify the situation

   Why: Rule 14(c) resolves ambiguity with a safety default: assume it is head-on and apply Rule 14 — alter to starboard. This prevents a vessel from standing on a potentially fatal course while waiting for certainty. The doubt signal is a general safety signal but is not the Rule 14(c) directive.

5. 5. Under Rule 16, the give-way vessel shall:

   • A.Sound the appropriate signal and then take action
   • B.Take early and substantial action to keep well clear✓
   • C.Reduce speed to half ahead and maintain course until the stand-on vessel reacts
   • D.Alter course to starboard in all situations

   Why: Rule 16 requires the give-way vessel to take early and substantial action to keep well clear. 'Early' prevents last-minute maneuvers; 'substantial' ensures the action is perceptible to the stand-on vessel; 'well clear' sets a high standard that goes beyond merely avoiding collision.

6. 6. Under Rule 17(b), when a stand-on vessel finds herself so close to the give-way vessel that collision cannot be avoided by the give-way vessel alone, the stand-on vessel shall:

   • A.Maintain course and speed to avoid confusing the give-way vessel
   • B.Sound five short blasts and reduce speed
   • C.Take such action as will best aid to avoid collision✓
   • D.Alter course to starboard regardless of the position of the give-way vessel

   Why: Rule 17(b) converts the stand-on vessel's permission into a duty once collision cannot be avoided by the give-way vessel alone. At that point the stand-on vessel must take whatever action best avoids collision — this is the in-extremis provision. The specific action depends on circumstances; starboard is not always the answer.

7. 7. In a narrow channel, the overtaking vessel sounds two prolonged blasts followed by two short blasts. What does this signal mean?

   • A.I intend to pass you on your starboard side
   • B.I intend to pass you on your port side✓
   • C.I am altering course to port
   • D.I am operating astern propulsion

   Why: Two prolonged blasts followed by two short blasts (Rule 34(c)(ii)) signals the overtaking vessel's intent to pass on the other vessel's port side. Two prolonged + one short = pass on starboard side. This signal is only used where the vessel being overtaken must maneuver to permit safe passing.

8. 8. You are overtaking another vessel in a narrow channel and intend to pass on the other vessel's starboard side. Under Rule 9(e), what signal do you sound?

   • A.Two prolonged blasts followed by one short blast✓
   • B.One prolonged blast followed by one short blast
   • C.Two short blasts
   • D.One prolonged blast followed by two short blasts

   Why: Rule 9(e)(i) specifies that a vessel intending to overtake on the other vessel's starboard side shall indicate intent by sounding two prolonged blasts followed by one short blast on the whistle.

Frequently asked questions

When is a vessel considered to be overtaking under Rule 13?

A vessel is overtaking when it is coming up with another vessel from a direction more than 22.5 degrees abaft the beam of that vessel. At night, the practical test is whether you can see only the white sternlight with no colored sidelights. Any doubt about whether this applies must be resolved by assuming it does.

Does a sailing vessel have to give way to a power vessel when overtaking?

Yes. Rule 13 specifically overrides the normal hierarchy of vessels. Any vessel overtaking any other vessel must keep out of the way of the vessel being overtaken, regardless of vessel type. A sailing vessel overtaking a power-driven vessel must give way.

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