46 CFR § 120.550
General alarm systems
April 15, 2021
(a) All vessels with overnight accommodations must be equipped with a general alarm system.
(b) A vessel of more than 19.8 meters (65 feet) in length with overnight accommodations for more than 49 passengers must have a general alarm that meets the requirements of §113.25 in subchapter J of this chapter.
(c) The public address system required by §121.610 of this chapter may be used to sound the general alarm signal.