IALACOLREG
View your progress
13

Overtaking

A vessel coming up from directly astern illustrates overtaking. Rule 13 covers approach from more than 22.5° abaft the beam. The overtaking vessel keeps out of the way until finally past and clear; no passing side is prescribed here.

Rule 13 establishes the overtaking rule. Any vessel overtaking any other shall keep out of the way of the vessel being overtaken.

a
Notwithstanding anything contained in the Rules of Part B, Sections I and II, any vessel overtaking any other shall keep out of the way of the vessel being overtaken.
b
A vessel shall be deemed to be overtaking when coming up with another vessel from a direction more than 22.5 degrees abaft her beam, that is, in such a position with reference to the vessel she is overtaking that at night she would be able to see only the sternlight of that vessel but neither of her sidelights.
c
When a vessel is in any doubt as to whether she is overtaking another, she shall assume that this is the case and act accordingly.
d
Any subsequent alteration of the bearing between the two vessels shall not make the overtaking vessel a crossing vessel or relieve her of the duty of keeping clear until she is finally past and clear.
Direct stern view shows a white sternlight. When coming up from the overtaking sector at night, this light can be seen but neither sidelight. A single white light alone does not establish vessel type or an overtaking situation.
Coming up from more than 22.5° abaft the beam: the overtaking vessel keeps out of the way until finally past and clear. If in doubt, assume overtaking.

IMO COLREG 1972Official text

Full wording of the rule, reproduced from the official source below.

(a) Notwithstanding anything contained in the Rules of Part B, Sections I and II, any vessel overtaking any other shall keep out of the way of the vessel being overtaken. (b) A vessel shall be deemed to be overtaking when coming up with another vessel from a direction more than 22.5° abaft her beam, that is, in such a position with reference to the vessel she is overtaking, that at night she would be able to see only the sternlight of that vessel but neither of her sidelights. (c) When a vessel is in any doubt as to whether she is overtaking another, she shall assume that this is the case and act accordingly. (d) Any subsequent alteration of the bearing between the two vessels shall not make the overtaking vessel a crossing vessel within the meaning of these Rules or relieve her of the duty of keeping clear of the overtaken vessel until she is finally past and clear.
Source:

STCW Bridge Watch Lens

Rules 4–10 apply in any visibility.

Rules 11–18 apply to vessels in sight of one another; Rule 19 applies to vessels not in sight when navigating in or near an area of restricted visibility.

Build the traffic picture with sight, hearing, radar/ARPA and chart context.

Do not let AIS or one isolated bearing replace systematic observation.

After manoeuvring, keep monitoring bearing, range, CPA/TCPA and passing distance until the other vessel is finally past and clear.

Exam Focus

Identify the vessel types first, then the relative bearing, then whether one vessel is overtaking.

Misclassifying the encounter is the usual exam failure.

For vessels in sight, every overtaking vessel keeps clear until finally past and clear.

Rule 13 takes precedence over Part B Sections I and II; it does not override the other Parts of COLREG.

Key Takeaways

1

In an in-sight overtaking encounter, the overtaking vessel keeps clear

2

Overtaking means approaching from more than 22.5 degrees abaft the other vessel's beam

3

If in doubt, assume you are overtaking

4

Bearing changes do not end the duty: remain clear until finally past and clear

Common Mistakes

Claiming crossing rights after initially being in an overtaking position

Not recognizing the overtaking sector (more than 22.5 degrees abaft beam)

Test Your Knowledge

Practise this topic and review the explanation for each answer.

More rules in this Part

Last reviewed:

Frequently asked questions about COLREG Rule 13

Which vessel must keep out of the way when overtaking?

The overtaking vessel. Any vessel overtaking any other shall keep out of the way of the vessel being overtaken, notwithstanding anything contained in the Rules of Part B, Sections I and II (Rule 13(a)).

When is a vessel deemed to be overtaking under COLREG Rule 13?

When coming up with another vessel from a direction more than 22.5 degrees abaft her beam — a position from which, at night, she would see only the sternlight of that vessel but neither of her sidelights (Rule 13(b)).

What should you do if you are in doubt whether you are overtaking?

Assume that 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.

Can an overtaking vessel become a crossing vessel as the bearing changes?

No. 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 of the overtaken vessel until she is finally past and clear (Rule 13(d)).