BOTH INTERNATIONAL & INLAND You are approaching another vessel. She is about one mile distant and is on your starboard bow. You believe she will cross ahead of you. She then sounds a whistle signal of five short blasts. What action should you take?

Correct Answer: Option C — make a large course change, and slow down if necessary

Rule 34(d) defines the five short blasts as the danger signal, indicating doubt regarding the other vessel's actions. Under Rule 8, you must take positive, early action to avoid collision, which includes a large course change or slowing down, rather than waiting for further signals or assuming safe passage.