Task Force 31 Task Force 31 ( TF 31 ) was a US Navy task force active with the United States Third Fleet during World War II , and still ready to be activated today with today ' s Third Fleet . Task Force numbers were in constant use , and there were several incarnations of TF 31 during World War II . In its most known World War II guise , it was formed at the end of World War II , under Rear Admiral Oscar C . Badger II , to begin the occupation of Japan . The TF 31 combatant ships were the first to enter Tokyo Bay when the US was not certain what kind of reception was waiting from the Japanese . The Task Force transported US Marine units to the Miura Peninsula area of Japan , which forms the southwest arm of Tokyo Bay , for occupation duties . The Marines were tasked with securing the military bases at Yokosuka and demilitarizing the entire peninsula . History . Background . Anticipating a possible Japanese surrender , plans were underway for the occupation of Japan . General MacArthur ' s Operation Blacklist was chosen over Admiral Nimitz ' plan . Both commanders agreed that the prompt occupation of Japan was essential . Third Fleet , under Admiral Halsey , was the only unit deemed capable and ready to do this . " On 8 August , advance copies of Halsey ' s Operation Plan 10 – 45 for the occupation of Japan setting up Task Force 31 ( TF 31 ) , the Yokosuka Occupation Force , were distributed . The task force ' s mission , based on Nimitz ' s basic concept , was to clear the entrance to Tokyo Bay and anchorages , occupy and secure the Yokosuka Naval Base , seize and operate Yokosuka Airfield , support the release of Allied prisoners , demilitarize all enemy ships and defenses , and assist U . S . Army troops in preparing for the landing of additional forces . Three days later , Rear Admiral Badger , Commander , Battleship Division 7 , was designated by Halsey to be commander , TF 31 . " The existing Task Force 38 was also alerted . The 6th Marine Division , was tasked to provide a regiment for the land portion of the operation . The Fleet Landing Force was commanded by Brigadier General William T . Clement . The 4th Regiment was selected . The choice was symbolic as the Old 4th had been captured in the Philippines early in the war . The 4th , and additional support units , made up the 5 , 400 man Task Force Able . Beginning . The elements of TF 31 began loading the Marines and their equipment on 1945 - 08 - 14 . On the 18th , advance command elements of the task force on board the USS " Ozark " joined up with the USS " Missouri " in Task Force 38 . The Task Force was officially created on at 1400 on 1945 - 08 - 19 en route to Japan . Two landing plans were considered : landing at Zushi on the western side of the peninsula or at Zushi and Yokosuka on the Tokyo Bay side . It was decided not to risk entering the bay until the " threat of Japanese treachery " was dealt with . At sea , some 3 , 500 men were transferred between the ships to organize the assault units . On 1945 - 08 - 21 plans were changed to land at Yokosuka , the primary objective . This would reduce the forces ' exposure on two narrow roads from Zushi to Yokosuka . General MacArthur ' s choice of Zushi as his headquarters also was a factor in the decision . L - Day was originally scheduled for 1945 - 08 - 26 , but was delayed to the 28th by a typhoon developing 300 miles to the southeast that was going to delay USAAF operations for 48 hours . L - Day was again delayed until 1945 - 08 - 30 . Occupation . On 1945 - 08 - 27 , Japanese reported on board the " Missouri " and their pilots were sent on a destroyer to guide Task Force 31 into Yokosuka Bay . Minesweepers did a defensive sweep on the way in as the Japanese had not been able to sweep the approaches . That afternoon Task Force 31 anchored in Sagami Wan , just outside Tokyo Bay . At 0900 on 1945 - 08 - 28 , led by USS " San Diego " , the combat elements of Task Force 31 entered Tokyo Bay and by 1300 they were anchored in Yokosuka Bay . Vice Admiral Michitaro Totsuka reported on board the " San Diego " for instructions on securing and surrendering the Yokosuka base . Around that time , an advance party from the USAAF landed at Atsugi Airfield to prepare it for the L - Day landing of the 11th Airborne . On 1945 - 08 - 29 , Admiral Halsey arrived in Sagami Wan . Two POWs rescued earlier from the beach convinced him to start the POW rescue operations that day . " That evening , for the first time since Pearl Harbor , the ships of the Third Fleet were illuminated . As General Metzger later remembered : ' Word was passed to illuminate ship , but owing to the long wartime habit of always darkening ship at night , no ship would take the initiative in turning their lights on . Finally , after the order had been repeated a couple of times lights went on . It was a wonderful picture with all the ships flying large battle flag s both at the foretruck and the stern . In the background was snowcapped Mount Fuji . ' Movies were shown on the weather decks . While the apprehension of some lessened , lookouts were still posted , radar s continued to search , and the ships remained on alert . " Before dawn on L - Day , 1945 - 08 - 30 , three groups of transports and escorts from TF 31 left Sagami Wan for Tokyo Bay . At 0558 , Marines landed on Fattsu Saki to secure the forts guarding Tokyo Bay , in coordination with the planned 0600 arrival of planes carrying the 11th Airborne at Atsugi Airfield . Finding the Japanese had followed the instructions on disabling their guns to the letter , the Marines quickly secured the forts and rejoined the task force at 0845 . At 0805 a small crew from USS " South Dakota " boarded the Japaneses battleship " Nagato " and received its surrender from a skeleton crew . 0930 on L - Day saw the Marines of 1st and 3rd Battalion landing at Yokosuka . The Japanese at the Yokosuka base had complied completely by disabling their weapons and removing all non - essential personnel . At 1030 the " San Diego " docked at Yokosuka . The formal surrender of the Japanese First Naval District by Admiral Totsuka to Rear Admiral Robert Carney , acting for Admiral Halsey , and Rear Admiral Badger took place at 1045 . Dissolution . After the delivery of the Marine occupation forces , TF 31 transport assets departed on 1 September to transport additional occupation troops . After the formal surrender of Japan on 1945 - 09 - 02 , Task Force 31 had completed its mission . By 6 September all Navy personnel and ships ' Marine detachments had returned to their ships from shore duties . On 1945 - 09 - 08 , Admiral Badger ' s Task Force 31 was dissolved . See also . United States Fleet Activities Yokosuka