In International and Inland rules, five short blasts when overtaking means what?

• A. I do not understand your intentions/Warning-Doubt
• B. I am operating astern propulsion
• C. No (Vessel may not overtake)
• D. I am altering my course to port

Answer: (C)

In this situation, sound signals are used to clearly communicate what each vessel intends to do while overtaking. Five short blasts is a deliberate warning that overtaking is not permitted at that moment. It tells the other vessel to refrain from passing because it would be unsafe or not allowed under the current conditions. The idea is to prevent a collision by making the intention unmistakable.

The other possibilities don’t fit because the distinct signals they describe correspond to different maneuvers or intentions, which are communicated by other sounds, not by five short blasts in this overtaking context.