Given the question: Information:  - In general, a civilian is "a person who is not a member of the military or of a police or firefighting force", as defined by Merriam Webster's Dictionary. From the perspective of the U.S. Department of Defense, Chapter 18 of Title 10 United States Code refers to non-military law enforcement officers as civilians since they are employees rather than enlisted personnel, and also in order to distinguish itself from military police. In military and law enforcement slang, the term "Civies" or "Civvies" are often used to refer civilian population or civilian clothing.  - USS Halcyon ( SP - 518 ) was a motor launch borrowed by the U.S. Navy from the U.S. Bureau of Fisheries during World War I. She was outfitted as a patrol craft and assigned to the 1st Naval District , headquartered at Portsmouth Navy Yard in Kittery , Maine . Post-war she was returned to the Bureau of Fisheries .  - The Isles of Shoals are a group of small islands and tidal ledges situated approximately off the east coast of the United States, straddling the border of the states of Maine and New Hampshire.  - Maine is the northernmost state in the New England region of the northeastern United States. Maine is the 39th most extensive and the 41st most populous of the U.S. states and territories. It is bordered by New Hampshire to the west, the Atlantic Ocean to the east, and the Canadian provinces of New Brunswick and Quebec to the north. Maine is the easternmost state in the contiguous United States, and the northernmost east of the Great Lakes. It is known for its jagged, rocky coastline; low, rolling mountains; heavily forested interior, and picturesque waterways; and also its seafood cuisine, especially clams and lobster. There is a continental climate throughout the state, even in coastal areas such as its most populous city of Portland. The capital is Augusta.  - World War I (WWI or WW1), also known as the First World War, or the Great War, was a global war originating in Europe that lasted from 28 July 1914 to 11 November 1918. More than 70 million military personnel, including 60 million Europeans, were mobilised in one of the largest wars in history. Over nine million combatants and seven million civilians died as a result of the war (including the victims of a number of genocides), a casualty rate exacerbated by the belligerents' technological and industrial sophistication, and the tactical stalemate caused by gruelling trench warfare. It was one of the deadliest conflicts in history, and paved the way for major political changes, including revolutions in many of the nations involved.  - Kittery is a town in York County, Maine, United States. Home to the Portsmouth Naval Shipyard on Seavey's Island, Kittery includes Badger's Island, the seaside district of Kittery Point, and part of the Isles of Shoals. The town is a tourist destination known for its many outlet stores.  - The Portsmouth Naval Shipyard (PNS), often called the Portsmouth Navy Yard, is a United States Navy shipyard located in Kittery on the southern boundary of Maine near the city of Portsmouth, New Hampshire. PNS is tasked with the overhaul, repair, and modernization of US Navy submarines. The facility is sometimes confused with the Norfolk Naval Shipyard in Portsmouth, Virginia.    Given the information above, choose from the list below the object entity that exhibits the relation 'operator' with the subject 'uss halcyon '.  Choices: - east coast  - portland  - refer  - southern  - united states navy
The answer is:
united states navy