49 CFR § 176.90 - Private automobiles.
(a) Class 1 (explosive) material. A private automobile which is carrying any Class 1 (explosive) material (except permitted fireworks or small arms ammunition) may not be transported on a passenger-carrying ferry vessel unless the Class 1 (explosive) material conforms to the packaging, labeling, marking, and certification requirements of this subchapter. Permitted fireworks and small arms ammunition may be carried without the required packaging, labeling, marking, or certification if they are in tight containers.
(b) Engines, gasoline, or liquefied petroleum gas. Engines, internal combustion, flammable gas powered or flammable liquid powered, including when fitted in machinery or vehicles (i.e. motor vehicles, recreational vehicles, campers, trailers), vehicle flammable liquid or flammable gas powered, gasoline, and petroleum gases, liquefied or liquefied petroleum gas when included as part of a motor home, recreational vehicle, camper, or trailer; are excepted from the requirements of this subchapter if the following conditions are met:
(1) Any container showing deterioration which might affect its integrity must not be allowed on board the vessel. A visual inspection by a responsible member of the crew must be made of each cylinder of liquefied petroleum gas before it may be allowed aboard the vessel. A cylinder that has a crack or leak, is bulged, has a defective valve or a leaking or defective pressure relief device, or bears evidence of physical abuse, fire or heat damage, or detrimental rusting or corrosion, may not offered for transportation on board the vessel. Leaking or damaged containers of gasoline may not be offered for transportation on board the vessel.
(2) Motor vehicles may be stowed in the same hold or compartment or on the vehicle deck of passenger vessels with cylinders of liquefied petroleum gas when the cylinders are securely attached to recreational vehicles, such as campers or trailers.
(3) Extra containers of gasoline (including camp stove or lantern fuel) and portable cylinders of liquefied petroleum gas (including cylinders for camping equipment) not securely attached to recreational vehicles must be stowed in the vessel's paint locker. Containers must be securely closed.
(4) All liquefied petroleum gas cylinders must be secured by closing the shut-off valves prior to the recreational vehicles being loaded on the vessels. The owner or operator of each recreational vehicle must be directed to close all operating valves within the vehicles.
(5) “No smoking” signs must be posted on the vehicle decks and, if used for storage of hazardous materials; in close proximity to the vessel's paint locker.
(6) An hourly patrol of the vehicle decks must be made by a crewmember. Any unusual or dangerous situation must be reported to the vessel's master.
(7) Passengers may be allowed on the vehicle decks during the voyage and are subject to the control of the crew personnel conducting the continuous vehicle deck patrol.
(8) Each person responsible for performing a function authorized by this section must be trained in accordance with subpart H of part 172 of this subchapter and on the requirements of this section.
(9) Shipments made under this paragraph are subject to the Incident Reporting requirements prescribed in §§ 171.15 and 171.16 of this subchapter.