Senior Officer Present Afloat, usually referred to as SOPA, is a U.S. Navy term to indicate the most senior officer present in a harbor occupied by more than one U.S. Navy vessel. That officer is essentially commander of all U.S. Navy operations afloat in the harbor, and is responsible to civilian authorities for the action of the ships and the behavior of crews under his or her command.
SOPA is a useful administrative function in foreign ports visited by U.S. Navy vessels. However, SOPA may also be established in continental U.S. ports.