IALACOLREG
13

Overtaking

Any vessel overtaking another shall keep out of the way of the vessel being overtaken.

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 these Rules, 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.
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.

STCW Bridge Watch Lens

1

Decide applicability before manoeuvring: Rules 4-10 apply in any visibility, Rules 11-18 only when vessels are in sight, and Rule 19 governs radar-only encounters in restricted visibility.

2

Build the traffic picture with sight, hearing, radar/ARPA and chart context. Do not let AIS or one isolated bearing replace systematic observation.

3

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

Exam Focus

1

Identify the vessel types first, then the relative bearing, then whether one vessel is overtaking. Misclassifying the encounter is the usual exam failure.

2

If two rules seem to conflict, check the order carefully: overtaking duties still apply, and Rule 2 still requires ordinary seamanship.

Key Takeaways

1

The overtaking vessel ALWAYS keeps clear

2

Overtaking defined as approaching from more than 22.5 degrees abaft the beam

3

If in doubt, assume you are overtaking

4

Once overtaking, always overtaking — even if bearings change

Common Mistakes

Claiming crossing rights after initially being in an overtaking position

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

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