46 CFR § 46.05-1
Passenger vessel
April 15, 2021
(a) For the purpose of the regulations in this part, a vessel is a passenger vessel if:
(1) Engaged on an international voyage by sea, it carries or is authorized to carry more than 12 passengers; or,
(2) Engaged on a coastwise voyage by sea or a voyage on the Great Lakes, it carries or is authorized to carry more than 16 persons in addition to the crew.