'Jamboree' was a series of US attacks on targets in the Japanese home islands by carrierborne aircraft of the US Navy’s Task Force 58 in the run-up to the 'Detachment' and 'Iceberg' landings on Iwo Jima and Okinawa (16/26 February 1945).
The Fast Carrier Task Force, known at different times as Task Force 38 (in the 3rd Fleet) and Task Force 58 (in the 5th Fleet), was the main striking force of the US Navy’s Pacific Fleet in the second half of the Pacific campaign of World War II. TF38 came into existence in August 1943 on the basis of the fleet carrier Saratoga and under the command of Rear Admiral Frederick C. Sherman. TF58 was created under the command of Vice Admiral Marc A. Mitscher on 6 January 1944.
TF38 continued to exist, with a handful of ships assigned, for two reasons. One was to confuse the Japanese, and the other for planning purposes when not in operational use. The same became true of Task Force 58.
The Fast Carrier Task Force comprised six fleet and six light aircraft carriers, together with a host of associated supporting ships. The force became TF38 again on 26 August 1944 under Admiral William F. Halsey, and grew to nine fleet aircraft carriers and eight light aircraft carriers in preparation for the US landings of October 1944 on the island of Leyte in the Philippine islands group. The FCTF became TF58 once again on 26 January 1945 under Admiral Raymond A. Spruance, then became TF38 under Halsey on 25 May 1945, remaining so until the end of the war.
'Jamboree' was carried out by Mitscher’s TF58. Ahead of the surface ships, the submarines Sterlet, Pomfret, Piper, Trepang, Bowfin, Sennet, Lagarto and Haddock were deployed along the approach route to locate and sink Japanese patrol boats.
TF58 departed Ulithi atoll on 10 February, completed exercises off Tinian island two days later, and refuelled from an underway replenishment group on 14 February 1. By day TG58.5 operated mostly with TG58.2. Ahead of TF58’s advance, four Japanese patrol boats had been sunk by the submarines, and six more were then sunk by a patrol line of destroyers (Haynsworth, Barton, Ingraham, Moale, Dortch and Waldron) advancing in front of the task force. The approach then moved forward without any major problem except damage to Ingram and Barton in a collision.
On 16 February, 145 miles (235 km) to the south-east of Tokyo, the carriers launched first their fighters to eliminate the Japanese defences in the air and on the ground, and then their bombers to attack, in particular, aircraft factories in the Tokyo area. The attacks were seriously impeded by the poor weather, however.
On 17 February the US carriers launched further attacks, this time concentrated on shipping off Yokohama: the 10,602-ton transport Yamashio Maru was sunk, and the frigate Amakusa and corvette Kaibokan 47 were damaged. Including fighter protection flights, the carriers flew 2,761 sorties, losing 60 aircraft in combat and 28 in accidents.
On 18 February the destroyers were refuelled, and TG58.4 made raids to neutralise Japanese air power on Haha-jima and Chichi-jima. TG58.1 and TG58.5 were detached for replenishment, and TF58 then returned to refuel near Chichi-jima. The battleships North Carolina and Washington, the heavy cruiser Indianapolis and two light cruisers were detached to strengthen the fire support operations against Iwo Jima from the east.
'Jamboree' thus began on 16 February with attacks on the Tokyo area, followed on 17 February with further attacks on Tokyo as well as Yokohama (the Tachikawa motor factory) and Kasumigaura, on 24 February with attacks on Tokyo, and on 26 February with attacks on Tokyo, the Hashino islands and Nagoya.
On 19/22 February TG58.2 and TG58.3, and from 20 February TG58.1, TG58.4 and TG58.5, supported the 'Detachment' landing on Iwo Jima from the west. On 23 February TF58 was brought together once more, and until 24 February replenished from the supporting ships of Rear Admiral Donald B. Beary’s Service Squadron 6.
On 25/26 February further carrier raids on the Tokyo area were badly impeded by the weather, and some had to be terminated prematurely. On 27 February there was an operation partly in support of operations on Iwo Jima, on 28 February further underway replenishment, and on 1 March a carrier raid on Okinawa in which the Japanese torpedo boat Manazuru and minesweeper Tsubame were sunk. The ships returned on 2 March and headed for Ulithi, which they reached on 4 March.