My modules›M1 COLREG›2. Look-out, safe speed, risk of collision and action to avoid it

Rule 4: Section I (Rules 4–10: look-out, safe speed, risk of collision, action, narrow channels, traffic separation) applies in any visibility.

Look-out, safe speed, risk of collision and action to avoid it

Rules 4–8

COLREG≈ 1 min read

4Application

In one sentence

Section I of COLREG still applies in any condition of visibility, from a clear day to fog.

The Rules in Section I apply in any condition of visibility; no condition is excluded.

Section I contains Rules 4 to 10: look-out, safe speed, risk of collision, action to avoid collision, narrow channels and traffic separation schemes.

It reminds you that Section I has a general scope; Section II points to vessels in sight of one another, and III to restricted visibility.

1
Application crosses visibility conditions → visibility does not switch it off.
2
Section I = Rules 4–10.
3
Topics: look-out · speed · collision · action · channels · separation.
4
Section II = vessels in sight · Section III = restricted visibility.

Wrong: "Section I applies only in clear visibility."
Right: It also applies in restricted visibility.
Wrong: "In fog, only the restricted-visibility Rules count."
Right: Rules 4 to 10 still apply; fog does not remove them.
Wrong: "Section I ends at Rule 9."
Right: It includes Rules 4 to 10, inclusive.

If an option limits Rule 4 to daylight, clear visibility or vessels in sight, reject that limit.
For a range question, look for 4–10; do not confuse Section I with Sections II or III.
If the stem says fog, check whether it asks about application, not which section is being referenced.

Read "any condition of visibility" literally: visibility does not switch Section I off.
Use 4–10 to locate Section I; references to II and III only guide how the question is framed.

IMO COLREG 1972U.S. Coast Guard — International Navigation Rules (2024)

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

Rules in this Section apply to any condition of visibility.

When you've read it, match the terms, then answer three questions. Get them all right to finish the unit; opening the page alone doesn't count.

No notes