FAQ: What Are Seaposts?
Ocean Post Offices were operated on all of the important transatlantic steamship lines. By the operation of the sea Post Office, the postal clerks sort the mail while the vessel is on her voyage, and have it all ready for delivery by the time port is reached, a saving of from twenty-four to fourty-eight hours' work for the postal force at either end of the route. On some of the steamship lines, the Post Office workers aboard were listed or included (as a separate line item) in their count of passengers aboard ship. They were highly successful and generated revenues for both the steamship lines and the Post Office.
Question submitted by: D. Morten