In a narrow channel, what signal should you sound when being overtaken by a vessel intending to pass on your starboard side?

• A. One prolonged, one short, one prolonged, and one short blast
• B. Five short blasts
• C. Two prolonged blasts
• D. One short blast

Answer: (A)

In a narrow channel, vessels use specific sound signals to clearly communicate maneuver intentions and avoid collisions. When you are being overtaken and the other vessel plans to pass on your starboard side, you should respond with a four-blast sequence: a long blast, a short blast, another long blast, then another short blast. This long–short–long–short pattern distinctly conveys that the overtaking vessel intends to pass on your starboard side, helping both vessels coordinate their movements in the restricted space.

Five short blasts is the general danger signal used in emergencies or to indicate danger; two prolonged blasts and a single short blast correspond to other maneuver indications and do not convey the overtaking-on-starboard intent in a narrow channel.