The owner, charterer, master, or managing operator of a vessel carrying overnight passengers shall have a suitable number of watchmen patrol throughout the vessel during the nighttime, whether or not the vessel is underway, to guard against, and give alarm in case of, a fire, man overboard, or other dangerous situation. [CGD 85-080, 61 FR 1005, Jan. 10, 1996, as amended at 62 FR 51359, Sept. 30, 1997]