46 C.F.R. § 113.50-10
Additional requirements for passenger vessels
Each passenger vessel must have a public address system capable of broadcasting separately or collectively to the following stations:
(a) Survival craft stations, port.
(b) Survival craft stations, starboard.
(c) Survival craft embarkation stations, port.
(d) Survival craft embarkation stations, starboard.
(e) Public spaces used for passenger assembly points.
(f) Crew quarters.
(g) Accommodation spaces and service spaces.