Rule 9 governs navigation in narrow channels and fairways.
STCW Bridge Watch Lens
In confined waters, think in terms of not impeding the vessel that is constrained by the channel or the traffic lane, then manoeuvre early to stay clear.
Build the traffic picture with sight, hearing, radar/ARPA and chart context.
Do not let AIS or one isolated bearing replace systematic observation.
After manoeuvring, keep monitoring bearing, range, CPA/TCPA and passing distance until the other vessel is finally past and clear.
Exam Focus
Start every scenario by classifying the encounter: overtaking, head-on, crossing, narrow channel, traffic separation, or restricted visibility.
If two rules seem to conflict, check the order carefully: overtaking duties still apply, and Rule 2 still requires ordinary seamanship.
Questions on channels and TSS often test the difference between 'keep out of the way' and 'shall not impede'.
Read that wording carefully.
Key Takeaways
In a narrow channel, keep as far to starboard as is safely practicable
Small craft, sailing craft and fishing vessels must not impede the ship that needs the channel
Crossing and overtaking are allowed only when they do not create danger for channel traffic
Anchoring in the channel should be avoided unless the circumstances genuinely require it
Common Mistakes
Treating a narrow channel like open water and drifting toward the middle or the wrong side
Crossing in front of a deep-draught or constrained vessel that has little room to manoeuvre
Test Your Knowledge
Test your knowledge and prove your mastery.