INTERNATIONAL ONLY You are in sight of a power-driven vessel that sounds two short blasts of the whistle. What does this signal mean?

Correct Answer: Option B — The vessel is altering course to port

Rule 34(a) mandates that two short blasts signify a vessel is altering her course to port. Under the International Rules, this signal is purely descriptive of the vessel's own movement and does not constitute a request or proposal for a specific passing side relative to the other vessel.