Supercargo

A supercargo (from Spanish sobrecargo) is a person employed on board a vessel by the owner of cargo carried on the ship.

[1] The duties of a supercargo are defined by admiralty law and include managing the cargo owner's trade, selling the merchandise in ports to which the vessel is sailing,[1] and buying and receiving goods to be carried on the return voyage.

[1] For instance, the supercargo has no authority over the stevedores, and has no role in the necessary preparatory work prior to the handling of cargo.

[1] During the Age of Sail from the 16th to the mid-19th century, the supercargo was the second-most important person aboard a merchant ship after the captain.

A new supercargo was always appointed for each journey; he had to keep books, notes and ledgers about everything that happened during the voyage and trade matters abroad.