COLREGs · Rule 13 · 33 CFR §83.13
Overtaking
Any vessel overtaking another shall keep out of the way of the vessel being overtaken. A vessel is overtaking when coming up from a direction more than 22.5° abaft the other's beam — i.e., she would see only the stern light at night.
What does Rule 13 actually say?#
Source
Practice this rule#
One real exam question on this rule, cited to source. No sign-up.
Under the Inland Rules, a vessel is in doubt as to whether she is in an overtaking situation with another vessel. Which action is required?
Does Inland Rule 13 change anything?#
Inland Rule 13 is 33 CFR §83.13, reproduced above, and carries no exam-relevant divergence from COLREGs Rule 13. One answer serves both the International and the Inland version of a Rules of the Road question on this rule — which is worth knowing precisely because several neighbouring rules do not work that way.
21 of 38 rules differ somewhere; the five the exam leans on are Rule 9, Rule 10, Rule 24, Rule 28 and Rule 34, side by side on Inland vs International Rules.
Why it shows up on the exam#
Overtaking trumps Rule 14 head-on and Rule 15 crossing — once the overtaking situation is established, it remains until the vessel is finally past and clear.
What does the exam actually test here?#
The geometry
More than 22.5° abaft the beam
A vessel is overtaking when coming up with another from a direction more than 22.5 degrees abaft her beam — the sector in which, at night, she would see only the other's sternlight and neither sidelight.
It outranks the others
Notwithstanding Rules 4–18
Rule 13 opens with 'notwithstanding anything contained in Rules 4 through 18'. Once overtaking is established, Rule 14 head-on and Rule 15 crossing do not reassign the duty.
It does not lapse
Until finally past and clear
Any subsequent alteration of the bearing between the two vessels does not make the overtaking vessel a crossing vessel or relieve her of the duty to keep clear until she is finally past and clear. In any doubt as to whether she is overtaking, a vessel shall assume that she is.
Rule 13 — common exam questions#
What makes a vessel an overtaking vessel?
Coming up with another vessel from a direction more than 22.5 degrees abaft her beam — the position from which, at night, only the sternlight of the other vessel would be visible and neither sidelight (33 CFR §83.13(b)).
If the bearing changes, does overtaking become a crossing situation?
No. Rule 13(d) says any subsequent alteration of the bearing between the two vessels shall not make the overtaking vessel a crossing vessel, nor relieve her of the duty of keeping clear until she is finally past and clear.
Which rule wins — Rule 13 or Rule 15?
Rule 13. It applies notwithstanding anything in Rules 4 through 18, so an overtaking vessel keeps out of the way even where the crossing rule would otherwise make the other vessel give way.
What if you are not sure whether you are overtaking?
Assume you are. Rule 13(c) requires a vessel in any doubt as to whether she is overtaking another to assume that this is the case and act accordingly.
Does Rule 13 apply to sailing vessels?
Yes. It says any vessel overtaking any other shall keep out of the way, so it covers sail overtaking sail and sail overtaking power alike.
Authoritative source#
- 33 CFR §83.13 — this section with its neighbours. 33 CFR Part 83 is public domain; checked 2026-05-16.
- COLREGs Rule 13 is published by the IMO and is authoritative internationally.
Practise this rule against the real exam.
Real exam questions. No signup, no card.
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