BOTH INTERNATIONAL & INLAND Two power-driven vessels are crossing as shown in illustration D042RR below. Vessel "A" sounds one short blast on the whistle. You are on vessel "B" and doubt that sufficient action is being taken by vessel "A" . What action should you take?

Correct Answer: Option A — Sound at least five short and rapid blasts

Rule 34(d) mandates the danger signal—at least five short and rapid blasts—whenever a vessel is in doubt regarding the other vessel's actions. This signal is the standard method to alert the other vessel that their current maneuvers are insufficient to prevent a collision, regardless of the initial signal given.