CR
COLREGTrainer
HomeStudyRulesPracticeExam
Sign in
CR
COLREG Trainer

The most advanced maritime training platform. Master COLREG and IALA rules with adaptive AI.

Resources

  • Pricing
  • Rules
  • Study

Legal

© 2026 ColregTrainer

Standard Verified
HomeStudyRulesPracticeExam
RulesRule 11
R10 Traffic separation sch…R10
11 / 44
R12 Sailing vesselsR12
Part B-IIBasic

Rule 11: Section II application

Section II applies only when vessels are visually in sight of each other.

Detailed Explanation

Rules 11 to 18 govern in-sight encounters. If vessels are not in sight and restricted visibility exists, Rule 19 is the governing framework.

Key Points

  • Section II requires vessels to be in visual contact
  • No visual sight in fog → apply Rule 19 instead
  • Even with radar: if you cannot see them, use Rule 19

Examples

  • Two cargo vessels see each other's navigation lights at 4 miles. They are in sight of one another, so Rules 11-18 govern the encounter — not Rule 19.
  • In patchy fog a vessel intermittently appears and disappears visually. Until positive visual contact is confirmed and sustained, you must still comply with Rule 19 rather than Section II.

Common Mistakes

  • Applying crossing or overtaking rules (Section II) to a radar-only target in fog instead of using Rule 19.
  • Forgetting that 'in sight' means visual contact only, not radar or AIS detection.

Related Rules

R4Section I applicatio…R19Conduct in restricte…
Mini Quiz

Rule 11: which statement is most correct in practice?

R10 Traffic separation sch…R10
11 / 44
R12 Sailing vesselsR12

Navigation

R11Section II applicationR12Sailing vesselsR13OvertakingR14Head-onR15CrossingR16Action by give-way vesselR17Action by stand-on vesselR18Responsibilities between ves…