BOTH INTERNATIONAL & INLAND You are underway in a narrow channel and you are being overtaken by a vessel astern. The overtaking vessel sounds a signal indicating his intention to pass your vessel on your starboard side. If such an action appears dangerous, which signal should you sound?

Correct Answer: Option B — Five short and rapid blasts

Rule 34(d) requires the use of the danger signal—five or more short and rapid blasts—whenever a vessel is in doubt regarding the safety or sufficiency of another vessel's actions. This applies to overtaking situations where the proposed maneuver by the overtaking vessel is perceived as hazardous by the stand-on vessel.