California Code, Business and Professions Code - BPC § 22300

No person issuing, selling or offering to sell any passage ticket or any instrument giving or purporting to give any right, either absolutely or upon any condition or contingency, to a passage or conveyance upon any vessel, or a berth or stateroom in any vessel, shall hold himself out to be or advertise himself in any way as the agent of the owner or consignees of such vessel or line, unless he has received authority in writing therefor, specifying the name of the company, line or vessel for which he is authorized to act as agent and the city or other place, together with the street and the street number, in which his office is kept for the sale of tickets, and unless such written authorization is readily available in such office.

This section shall not apply to the sale of passage tickets on board any such vessel or to the offices of the actual owners or consignees of such vessel.