IALACOLREG
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1

Application

Geographic scope: high seas and waters connected to them navigable by seagoing vessels.

Rule 1 applies COLREG to all vessels on the high seas and connected waters navigable by seagoing vessels.

b
Appropriate authorities may make special local rules for roadsteads, harbours, rivers, lakes and connected inland waterways. They must conform as closely as possible to COLREG.
c
Governments may prescribe additional station or signal lights, shapes or whistle signals for warships and vessels in convoy, and additional station or signal lights or shapes for vessels fishing as a fleet. So far as possible, these must not be mistaken for COLREG signals.
d
Traffic separation schemes may be adopted by the IMO for the purposes of these Rules.
e
If a government determines that a vessel of special construction or purpose cannot fully meet specified requirements for lights, shapes or sound-signalling appliances, the vessel must follow the alternative arrangements that government determines are the closest possible compliance. This is not a general exemption from collision-avoidance duties.

IMO COLREG 1972Official text

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

(a) These Rules shall apply to all vessels upon the high seas and in all waters connected therewith navigable by seagoing vessels. (b) Nothing in these Rules shall interfere with the operation of special rules made by an appropriate authority for roadsteads, harbors, rivers, lakes or inland waterways connected with the high seas and navigable by seagoing vessels. Such special rules shall conform as closely as possible to these Rules. (c) Nothing in these Rules shall interfere with the operation of any special rules made by the Government of any State with respect to additional station or signal lights, shapes or whistle signals for ships of war and vessels proceeding under convoy, or with respect to additional station or signal lights or shapes for fishing vessels engaged in fishing as a fleet. These additional station or signal lights, shapes or whistle signals shall, so far as possible, be such that they cannot be mistaken for any light, shape or signal authorized elsewhere under these Rules. (d) Traffic separation schemes may be adopted by the Organization for the purpose of these Rules. (e) Whenever the Government concerned shall have determined that a vessel of special construction or purpose cannot comply fully with the provisions of any of these Rules with respect to the number, position, range or arc of visibility of lights or shapes, as well as to the disposition and characteristics of sound-signaling appliances, such vessel shall comply with such other provisions in regard to the number, position, range or arc of visibility of lights or shapes, as well as to the disposition and characteristics of sound-signaling appliances, as her Government shall have determined to be the closest possible compliance with these Rules in respect to that vessel.
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

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

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

COLREG is not limited to merchant ships or blue-water passages

2

Local harbour and inland-water rules may supplement COLREG but should stay as close as possible to it

3

Special government light and signal rules exist for warships, convoys and fleet fishing

4

Traffic separation schemes used under COLREG are adopted through the IMO framework

Common Mistakes

Assuming COLREG only applies outside territorial waters

Treating local port rules as if they cancel the collision rules altogether

Test Your Knowledge

Practise this topic and review the explanation for each answer.

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Frequently asked questions about COLREG Rule 1

Which vessels and waters does COLREG Rule 1 apply to?

COLREG applies to all vessels upon the high seas and in all waters connected therewith that are navigable by seagoing vessels. It is not limited to merchant ships or to blue-water passages.

Do local harbour or inland rules replace the COLREGs?

No. Appropriate authorities may make special local rules for roadsteads, harbours, rivers, lakes and inland waterways connected with the high seas, but those rules must conform as closely as possible to COLREG. Treating local port rules as if they cancel the collision rules altogether is a common mistake.

Who adopts traffic separation schemes under the COLREGs?

Traffic separation schemes may be adopted by the IMO for the purposes of these Rules. A vessel still has to comply with the rest of COLREG unless a specific routing provision applies.