United States Pacific Command (USPACOM) is a unified combatant command of the United States Armed Forces responsible for the Indo-Asia-Pacific region.
 It is the oldest and largest of the unified combatant commands.
 Its commander, the senior U.S. military officer in the Pacific, is responsible for military operations in an area which encompasses more than 100 e6sqmi , or roughly 52 percent of the Earth’s surface, stretching from the waters off the west coast of the United States to the west coast of India, and from the Arctic to the Antarctic.
 The Commander reports to the President of the United States through the Secretary of Defense and is supported by Service component and subordinate unified commands, including U.S. Army Pacific, U.S. Pacific Fleet, U.S. Pacific Air Forces, U.S. Marine Forces Pacific, U.S. Forces Japan, U.S. Forces Korea, Special Operations Command Korea, and Special Operations Command Pacific.
 USPACOM also has three direct reporting units (DRUs), including Daniel K. Inouye Asia-Pacific Center for Security Studies, U.S. Pacific Command Joint Intelligence Operations Center, Center for Excellence in Disaster Management and Humanitarian Assistance; and a Standing Joint Task Force, Joint Interagency Task Force West.
 The USPACOM headquarters building, the Nimitz-MacArthur Pacific Command Center, is located on Camp H.M. Smith, Hawaii.
Eldon P. Wyman (11 January 1917 - 7 December 1941) was an ensign serving aboard the USS Oklahoma (BB-37) when the Japanese attacked Pearl Harbor on 7 December 1941.
 Wyman was among the sailors trapped inside the Oklahoma when it sank at its berth.
Pearl Harbor is a lagoon harbor on the island of Oahu, Hawaii, west of Honolulu.
 Much of the harbor and surrounding lands is a United States Navy deep-water naval base.
 It is also the headquarters of the United States Pacific Fleet.
 The U.S. government first obtained exclusive use of the inlet and the right to maintain a repair and coaling station for ships here in 1887.
 The attack on Pearl Harbor by the Empire of Japan on December 7, 1941, was the immediate cause of the United States' entry into World War II.
Lee Embree (July 9, 1915 – January 24, 2008) was an American Army staff sergeant and photographer who took the first American air-to-air photographs of the Japanese attack on Pearl Harbor in 1941.
 Embree took the pictures of the attack from on board an Army Air Corps B-17 which he happened to be flying on from California to Hawaii on December 7, 1941 as the Japanese attacked the Pacific Fleet stationed at Pearl Harbor.
The United States Pacific Fleet (USPACFLT) is a Pacific Ocean theater-level component command of the United States Navy that provides naval forces to the United States Pacific Command.
 Fleet headquarters is at Pearl Harbor Naval Station, Hawaii, with large secondary facilities at North Island, San Diego Bay on the Mainland.
Commander, Submarine Force, U.S. Pacific Fleet (COMSUBPAC) is the principal advisor to the Commander, United States Pacific Fleet (COMPACFLT) for submarine matters.
 The Pacific Submarine Force (SUBPAC) includes attack, ballistic missile and auxiliary submarines, submarine tenders, floating submarine docks, deep submergence vehicles and submarine rescue vehicles throughout the Pacific.
Service Forces, United States Pacific Fleet, usually known as COMSERVPAC, was a service support command of the United States Pacific Fleet from 1942 until 1973.
 It was the reincarnation of the former Base Force.
 The Service Force comprised the supply train of the fleet which includes Oilers (AO), Gasoline Tanker (AOG), Repair Ships (AR), Ammunition Ships (AE), Destroyer Tenders (AD) and Submarine tenders (AS).
The region's premier installation and headquarters installation, Joint Base Pearl Harbor–Hickam is host two of United States Pacific Command subordinate Service components - United States Pacific Fleet on the Pearl Harbor side, and Pacific Air Forces on the Hickam side.
 The region also oversees installation support for the Pacific Missile Range Facility, the world's largest instrumented, multi-dimensional testing and training missile range in Kekaha, Hawaii.
The United States Fleet Marine Force, Pacific (FMFPAC) is the largest maritime landing force in the world.
 Its units are spread across the Pacific Ocean and reports to the United States Pacific Command.
 It is headquartered at MCB Camp H. M. Smith, HI and directs and commands all the subordinate elements of the Navy Expeditionary Strike Force and Marine Air-Ground Task Force components that follow under the 3rd, 5th, and 7th Fleet and the Marine Corps Forces, Pacific (MARFORPAC).
 The Commanding General of Marine Corps Forces, Pacific is dual-posted as the Commanding General of Fleet Marine Force, Pacific.
 FMFPAC is under operational control of the Commander, United States Pacific Fleet (COMPACFLT), when deployed.
Destroyer Force, United States Pacific Fleet, usually known as COMDESPAC, was a type command of the United States Pacific Fleet from 1940 until the Destroyer Force was combined with Cruisers, Pacific Fleet and in 1975 type command functions of both were transferred to Commander, Naval Surface Forces Pacific.
 The Pacific Fleet Destroyer Force comprised the Destroyers of the fleet (DD) operating in Pacific Fleet area of responsibility.
 The Commander, Destroyers, Pacific Fleet supervised the assignments, basing, maintenance of the destroyers, the training of crews and reported to the Commander in Chief, United States Pacific Fleet (CinCPac), on Destroyer operations.

Question: Eldon P. Wyman was an ensign on the USS Oklahoma when the Japanese attacked what lagoon harbor that is the headquarters of the United States Pacific Fleet?
Answer: Pearl Harbor