Question: Submarine Squadron 7 is a squadron of submarines of the United States Navy based at Joint Base Pearl Harbor-Hickam,Pearl Harbor, a lagoon harbor on what island?
Context: Submarine Squadron 1 (also known as SUBRON 1) is a squadron of submarines of the United States Navy based at Joint Base Pearl Harbor-Hickam, Pearl Harbor, Hawai'i.  The submarines that make up SUBRON 1 include: The 96th Air Refueling Squadron was a unit of PACAF's 15th Wing at Joint Base Pearl Harbor-Hickam, Hawaii in partnership with the 203rd Air Refueling Squadron and 154th Maintenance Group of the Hawaii Air National Guard.  It was inactivated on 3 September 2015. Submarine Squadron 7 (also known as SUBRON 7) is a squadron of submarines of the United States Navy based at Joint Base Pearl Harbor-Hickam, Pearl Harbor, HI under the command of Captain Craig Blakely Submarine Squadron 3 (also known as SUBRON 3) was a squadron of submarines of the United States Navy based at Joint Base Pearl Harbor-Hickam, Pearl Harbor, HI which was disestablished in 2012. USS "Denver" (LPD-9), an "Austin"-class amphibious transport dock, is the third ship of United States Navy to bear this name.  "Denver"' s keel was laid 7 July 1964 at Lockheed Shipbuilding and Construction Company, Seattle, Washington.  She was launched 23 January 1965, christened by Mrs. John A. Love, wife of the Governor of Colorado, and commissioned 26 October 1968.  After 46 years of service, the "Denver" was decommissioned at Joint Base Pearl Harbor-Hickam on 14 August 2014.  At the time of her decommissioning, "Denver" was the oldest deployable warship in the U.S. Navy, and the last active warship to be in Vietnam. The HA.  19 (also known as Japanese Midget Submarine "C" by the US Navy) is a historic Imperial Japanese Navy "Type A Kō-hyōteki"-class midget submarine that was part of the Japanese attack on Pearl Harbor on 7 December 1941.  This submarine was ordered to enter Pearl Harbor then attack the American warships with its torpedoes and then be scuttled with explosives next to a warship.  However, she did not enter the harbor, and was grounded and captured.  The submarine was eventually put on display near the submarine squadron at Naval Station Key West, Florida, then moved to the nearby Key West Lighthouse and Military Museum.  "HA.  19" is now displayed at the National Museum of the Pacific War in Fredericksburg, Texas. Herbert J. "Hawk" Carlisle (born 1957) is a retired United States Air Force four-star general who last served as the commander of Air Combat Command (ACC), at Langley Field, Joint Base Langley–Eustis, Virginia.  He also previously served as the commander of Pacific Air Forces while concurrently serving as Air Component Commander for United States Pacific Command and executive director of Pacific Air Combat Operations Staff, Joint Base Pearl Harbor-Hickam, Hawaii.  He will officially retire from the Air Force on May 1, 2017 with 39 years of service. Hickam Air Force Base is a United States Air Force installation, named in honor of aviation pioneer Lieutenant Colonel Horace Meek Hickam.  The base merged with the Naval Base Pearl Harbor to become part of the Joint Base Pearl Harbor–Hickam.  The base neighbors Honolulu International Airport and currently shares runways with the airport for its activities and purposes. The United States Air Force's 324th Intelligence Squadron is an intelligence unit located at Joint Base Pearl Harbor-Hickam, Hawaii. 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.
Answer: Oahu