BOTH INTERNATIONAL & INLAND When a vessel signals her distress by means of a gun or other explosive signal, which firing intervals should be used?

Correct Answer: Option C — Once every minute

Annex IV, paragraph 1(c) specifies that the firing of a gun or other explosive signal as a distress signal must be performed at intervals of about one minute. This specific timing ensures the signal is distinct from other navigational sounds and allows for effective localization by potential rescuers.