IALACOLREG
11

Application

Rules in this Section apply to vessels in sight of one another.

Rule 11 states that the rules in Section II (Rules 11–18) apply only to vessels in sight of one another. Two vessels are "in sight" when one can be observed visually from the other. Radar observation alone does not constitute being "in sight."

STCW Bridge Watch Lens

1

Decide applicability before manoeuvring: Rules 4-10 apply in any visibility, Rules 11-18 only when vessels are in sight, and Rule 19 governs radar-only encounters in restricted visibility.

2

Build the traffic picture with sight, hearing, radar/ARPA and chart context. Do not let AIS or one isolated bearing replace systematic observation.

3

After manoeuvring, keep monitoring bearing, range, CPA/TCPA and passing distance until the other vessel is finally past and clear.

Exam Focus

1

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

2

If two rules seem to conflict, check the order carefully: overtaking duties still apply, and Rule 2 still requires ordinary seamanship.

Key Takeaways

1

Section II only applies when vessels can see each other visually

2

Radar contact alone does not mean vessels are 'in sight'

3

In restricted visibility, Section III (Rule 19) applies instead

Common Mistakes

Applying crossing or overtaking rules when only detected on radar

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