(a) This section applies to a merchant vessel of at least 100 gross tons as measured under section
14502 of this title, or an alternate tonnage measured under section
14302 of this title as prescribed by the Secretary under section
14104 of this title except
(1) a vessel operating only on rivers and lakes (except the Great Lakes);
(2) a barge (except a seagoing barge or a barge to which chapter
37 of this title applies);
(3) a fishing, fish tender, or whaling vessel or a yacht;
(4) a sailing
school vessel with respect to sailing
school instructors and sailing
school students;
(5) an oceanographic research vessel with respect to scientific personnel;
(6) a fish processing vessel entered into service before January 1, 1988, and not more than 1,600 gross tons as measured under section
14502 of this title, or an alternate tonnage measured under section
14302 of this title as prescribed by the Secretary under section
14104 of this title or entered into service after December 31, 1987, and having not more than 16 individuals on board primarily employed in the preparation of fish or fish products;
(7) a fish processing vessel (except a vessel to which clause (6) of this subsection applies) with respect to individuals on board primarily employed in the preparation of fish or fish products or in a support position not related to navigation;
(8) a mobile offshore drilling unit with respect to individuals, other than crew members required by the certificate of inspection, engaged on board the unit for the sole purpose of carrying out the industrial business or function of the unit;
(9) a passenger vessel not engaged in a foreign voyage with respect to individuals on board employed for a period of not more than 30 service days within a 12 month period as entertainment personnel, with no duties, including emergency duties, related to the navigation of the vessel or the safety of the vessel, its crew, cargo or passengers; and
(10) the Secretary may prescribe the individuals required to hold a merchant mariners document serving onboard an oil spill response vessel.
(b) A person may not engage or employ an individual, and an individual may not serve, on board a vessel to which this section applies if the individual does not have a merchant mariners document issued to the individual under section
7302 of this title. Except for an individual required to be licensed or registered under this part, the document must authorize service in the capacity for which the holder of the document is engaged or employed.
