IALACOLREG
3

General Definitions

Defines key terms used throughout the COLREGs including vessel, power-driven vessel, sailing vessel, restricted visibility, and more.

Rule 3 provides essential definitions used throughout the COLREGs. Key definitions include:

a
The word "vessel" includes every description of water craft, including non-displacement craft, WIG craft and seaplanes, used or capable of being used as a means of transportation on water.
b
The term "power-driven vessel" means any vessel propelled by machinery.
c
The term "sailing vessel" means any vessel under sail provided that propelling machinery, if fitted, is not being used.
d
The term "vessel engaged in fishing" means any vessel fishing with nets, lines, trawls or other fishing apparatus which restrict manoeuvrability, but does not include a vessel fishing with trolling lines or other fishing apparatus which do not restrict manoeuvrability.
e
The word "seaplane" includes any aircraft designed to manoeuvre on the water.
f
The term "vessel not under command" means a vessel which through some exceptional circumstance is unable to manoeuvre as required by these Rules and is therefore unable to keep out of the way of another vessel.
g
The term "vessel restricted in her ability to manoeuvre" means a vessel which from the nature of her work is restricted in her ability to manoeuvre as required by these Rules.

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

Start every scenario by classifying the encounter: overtaking, head-on, crossing, narrow channel, traffic separation, or restricted visibility.

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

A vessel under sail using its engine is classified as power-driven

2

Fishing vessels must have apparatus that restricts manoeuvrability

3

NUC status requires exceptional circumstances preventing manoeuvring

4

RAM status comes from the nature of the work being performed

Common Mistakes

Classifying a sailing vessel with engine running as a sailing vessel

Confusing NUC with RAM — NUC is exceptional, RAM is work-related

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