Captain of the port

The captain of the port is an official who has different functions in the United Kingdom, the United States, and other countries.

United Kingdom
In the Royal Navy, the captain of the port is the officer, usually with the rank of captain, responsible for the day-to-day running of a Naval Dockyard under the authority of the admiral-superintendent. He usually also holds the position of Queen's or King's harbourmaster and was directly responsible for the captain's department, which among other things operated the yard craft.

To some extent the role of captain of the port is analogous to that of a harbourmaster.

United States
In the United States, captain of the port (COTP) is a title held by a United States Coast Guard officer, usually the commander of a United States Coast Guard sector with the rank of captain (O-6). Captain of the port duties involve enforcing within their respective areas port safety and security and marine environmental protection regulations, including regulations for the protection and security of vessels, harbors, and waterfront facilities; anchorages; security zones; safety zones; regulated navigation areas; deepwater ports; water pollution; and ports and waterways safety.