Two long, one short
Overtaking in a narrow channel. Advanced level, about 2 min. COLREGs Rules 9(e) & 34(c).
The situation
You are proceeding up a narrow channel. A faster vessel is coming up astern of you and sounds a signal. Play it and decide what she proposes.
What does she intend?
- “I intend to overtake you on your starboard side”: Two prolonged blasts and one short.
- “I intend to overtake you on your port side”: Two prolonged blasts and two short.
- “I agree to be overtaken”: Prolonged, short, prolonged, short.
Lookout: In a narrow channel the overtaking signals start with two prolonged blasts. The short blasts that follow say which side: one for starboard, two for port.
The sound answer
“I intend to overtake you on your starboard side”
Rule 34(c)(i): two prolonged blasts followed by one short means “I intend to overtake you on your starboard side”. If you agree, reply prolonged, short, prolonged, short, and take steps to permit safe passing; if in doubt, sound five short blasts.
Why the other options fall short
“I intend to overtake you on your port side”
Overtaking on your port side would be two prolonged blasts followed by two short. This signal ended with one short blast.
“I agree to be overtaken”
Agreement is the reply from the vessel about to be overtaken: one prolonged, one short, one prolonged and one short. It is your answer to this signal, not the signal itself.
Rules 9(e) & 34(c) · Overtaking in a narrow channel
In a narrow channel, a vessel intending to overtake signals two prolonged blasts followed by one short (starboard side) or two short (port side). The vessel being overtaken agrees with prolonged, short, prolonged, short, and takes steps to permit safe passing.