The rule in plain words
- What does it establish?The Rules in Section I apply in any condition of visibility; no condition is excluded.
- What does it include?Section I contains Rules 4 to 10: look-out, safe speed, risk of collision, action to avoid collision, narrow channels and traffic separation schemes.
- Why does it help?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.
Before you read on: what would you do?
Question 1/1
What happens to Section I in fog?
Frequent mistakes
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.
Exam keys & interpretation
- 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.
How to read it
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.
Key points
- Application crosses visibility conditions → visibility does not switch it off.
- Section I = Rules 4–10.
- Topics: look-out · speed · collision · action · channels · separation.
- Section II = vessels in sight · Section III = restricted visibility.
Test your knowledge
3 questions to check it. Pick an answer to see why.
Question 1/3
Which range identifies Section I?