The said extra compensation shall be paid by the master, owner, agent, or consignee of such vessel or other conveyance arriving in the United States from a foreign port to the Attorney General, who shall pay the same to the several immigration officers and employees entitled thereto as provided in this section and . Such extra compensation shall be paid if such officers or employees have been ordered to report for duty and have so reported, whether the actual inspection or examination of passengers or crew takes place or not: That this section shall not apply to the inspection at designated ports of entry of passengers arriving by international ferries, bridges, or tunnels, or by aircraft, railroad trains, or vessels on the Great Lakes and connecting waterways, when operating on regular schedules.section 1353a of this titleProvided,