1The rule in plain words
In one sentence…
COLREG reserves the rules in this section for vessels in sight of one another.
When does Section II apply?
Rules 12 to 18 of COLREG apply only when the vessels are in sight of one another: it is enough that one can see the other by eye.
What does in sight mean?
Check Rule 3(k): you must be able to see the other vessel; radar-only contact does not meet the visual condition.
What if they are not in sight?
If vessels are not in sight in or near restricted visibility, don't use this section: consult Rule 19.
2Key points
- 1.
Section II → visual encounter, not abstract detection.
- 2.
Rules 12–18: only within this situation.
- 3.
Radar alone: does not activate this section.
- 4.
Restricted visibility without sighting → check Rule 19.
3Frequent mistakes
Wrong: "Radar contact means we are in sight."
Right: Radar does not replace the visual contact required by Rule 11.
Wrong: "Section II applies even when you cannot see the other vessel."
Right: It applies only to vessels in sight of one another.
Wrong: "Rule 11 and Rule 19 are the same thing."
Right: For vessels not in sight in restricted visibility, consult Rule 19.
4Exam keys & interpretation
Exam keys
"Only" is decisive: if neither vessel can see the other, do not choose the rules in this section.
Radar without sighting: the question tests Rule 11's scope, not a manoeuvre.
In or near restricted visibility + not in sight → look for Rule 19.
How to read it
Read "in sight" literally: one must be able to observe the other visually; electronic detection is not enough.
Separate the situations: if one sees the other, this section; no sight in restricted visibility, Rule 19.
5Official text
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 vessels in sight of one another.6Test your knowledge
When do the rules in Section II apply?
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