The Captain of the Port is an official who has different functions in the United Kingdom

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 and the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

.

United Kingdom

In the Royal Navy

Royal Navy

The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

, the Captain of the Port is the officer, usually with the rank of Captain

Captain (naval)

Captain is the name most often given in English-speaking navies to the rank corresponding to command of the largest ships. The NATO rank code is OF-5, equivalent to an army full colonel....

, responsible for the day-to-day running of a Naval Dockyard

Royal Navy Dockyard

Royal Navy Dockyards are harbours where either commissioned ships are based, or where ships are overhauled and refitted. Historically, the Royal Navy maintained a string of dockyards around the world, although few are now operating today....

 under the authority of the Admiral-Superintendent

Admiral-Superintendent

The Admiral-Superintendent was the Royal Navy officer in command of a larger Naval Dockyard. Portsmouth, Devonport and Chatham all had Admiral-Superintendents, as did some other dockyards in the United Kingdom and abroad at certain times. The Admiral-Superintendent usually held the rank of...

. He usually also holds the position of Queen's or King's Harbourmaster

Harbourmaster

A harbourmaster is an official responsible for enforcing the regulations of a particular harbour or port, in order to ensure the safety of navigation, the security of the harbour and the correct operation of the port facilities.-Responsibilities:Harbourmasters are normally responsible for issuing...

 and was directly responsible for the Captain's Department, which among other things operated the yard craft

Admiralty Yard Craft Service

The Admiralty Yard Craft Service was the civilian service which operated auxiliary vessels for the British Admiralty, mainly in HM Dockyards or the vicinity. It was renamed the Port Auxiliary Service between 1960 and 1962, and later the Royal Maritime Auxiliary Service after 1970.The service...

.

United States

In the United States of America, Captain of the Port (COTP) is a title held by a U.S. Coast Guard

United States Coast Guard

The United States Coast Guard is a branch of the United States Armed Forces and one of the seven U.S. uniformed services. The Coast Guard is a maritime, military, multi-mission service unique among the military branches for having a maritime law enforcement mission and a federal regulatory agency...

 officer, usually the Commander

Sector Commander

Sector Commander is the position title of the commanding officer of a United States Coast Guard Sector, usually of the rank of Captain . The Sector Commander's second-in-command is the Deputy Sector Commander...

 of a United States Coast Guard Sector

United States Coast Guard Sectors

A Sector is a shore-based operational unit of the United States Coast Guard. Each Sector is responsible for the execution of all Coast Guard missions within its Area of Responsibility , with operational support from Coast Guard Cutters and Air Stations. Subordinate commands within a 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.