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.
The supercargo has control of the cargo unless limited by other contracts or agreements.[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. Sailing from port to port with the vessel to which they are attached, supercargos differ from factors, who have a fixed place of residence at a port or other trading place.[1]