Crossing a buoyed channel
Narrow channel. Developing level, about 3 min. COLREGs Rule 9.
The situation
You are in a 12 m motor boat, about to cross a buoyed approach channel heading west. Northern Star, a 120 m cargo ship that can navigate safely only within the channel, is coming up it. She is on your port side, on a steady bearing.
How do you cross?
- Stop short of the channel and let her pass: Cross astern once she is clear.
- Stand on: she is on your port side: Apply the crossing rule.
- Speed up and cross ahead of her: Get across before she arrives.
Lookout: A ship confined to a channel has little room to manoeuvre and needs a long distance to stop. The crossing rule is not the whole story here.
The sound answer
Stop short of the channel and let her pass
Rule 9(b) and (d): a vessel of less than 20 m, or a vessel crossing, shall not impede the passage of a vessel that can safely navigate only within the channel. Waiting outside the marks and crossing astern is the authored example.
Why the other options fall short
Stand on: she is on your port side
In a narrow channel, Rule 9 says you shall not impede her passage, regardless of which side she is on. Expecting a 120 m ship confined to the channel to give way to you is a classic and dangerous mistake.
Speed up and cross ahead of her
Racing across the bow of a vessel confined to a channel is exactly the impeding Rule 9 forbids, and it leaves no margin if anything goes wrong.
Rule 9 · Narrow channels
A vessel of less than 20 m, a sailing vessel and a vessel crossing shall not impede the passage of a vessel that can safely navigate only within a narrow channel or fairway. A vessel shall not cross a narrow channel if doing so impedes such a vessel.