BOTH INTERNATIONAL & INLAND A vessel showing a rigid replica of the International Code flag "A" is engaged in which operation?

Correct Answer: Option D — diving operations

Rule 27(d)(iii) requires a vessel engaged in diving operations to display a rigid replica of the International Code flag 'A'. This signal warns other vessels that divers are in the water and that the vessel is restricted in its ability to maneuver, necessitating a wide berth.