Senior Officer Present Afloat, usually referred to as SOPA, is a U.S. Navy term to indicate the U.S. Navy officer, with the highest ranking by rank, or number in rank, 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.
SOP(A) is the term used for "Senior Officer Present (Ashore)."
This article incorporates text from the public domain Dictionary of American Naval Fighting Ships.