Which vessel must have a gong, or other equipment which will make the sound of a gong?

• A. Vessel not under command
• B. Vessel restricted in her ability to maneuver
• C. Vessel fishing
• D. Any vessel over 100 meters

Answer: (D)

Sound signaling equipment requirements are tied to vessel size, not just what a vessel is doing. Large ships must carry a gong or an equivalent device because a gong provides a loud, distinct sound that can be heard over long distances and in rough conditions, helping other vessels determine presence and course in poor visibility. Therefore, vessels 100 meters or more in length are required to have a gong or something that produces the same sound signal. The other options describe vessel status or activity, which affect signaling in certain situations, but they do not establish the mandatory equipment based on size.