BOTH INTERNATIONAL & INLAND A vessel displaying the shape shown in illustration D013RR below is doing which of the following?

Correct Answer: Option B — anchored

Rule 30(a) requires a vessel at anchor to exhibit a black ball in the forepart of the vessel where it can best be seen. This shape serves as the standard daylight signal for an anchored vessel, ensuring other mariners can identify the vessel's status and avoid potential collision risks.