South Pacific Area The South Pacific Area ( SOPAC ) was a multinational U . S . - led military command active during World War II . It was a part of the U . S . Pacific Ocean Areas under Admiral Chester Nimitz . Instructions to the senior U . S . Army officer of the command , dated 7 July 1942 , said : " The establishment of the Pacific Ocean Area as an area of United States strategical responsibility under the command of the Commander - in - Chief , U . S . Pacific Fleet , became effective on May 8 , 1942 . The Commander - in - Chief , U . S . Pacific Fleet , has been designated the " Commander - in - Chief , Pacific Ocean Area " . Under the Commander - in - Chief , Pacific Ocean Area , a U . S . Naval officer has been designated as " Commander , South Pacific Area " . The South Pacific Force under COMSOPAC include the following : In July 1942 the South Pacific Area , under Admiral Ghormley , superseded by Admiral William Halsey Jr . from 16 October , comprised four commands : Amphibious Forces , South Pacific ( AmphibForSoPac ) , under Admiral Richmond K . Turner , South Pacific Naval Forces under Admiral Ghormley , U . S . Army Forces South Pacific under Major General Millard Harmon , and South Pacific Air Forces under Admiral John S . McCain , Sr . . At a later stage Transport Group , South Pacific ( TransGrpSoPac ) was added to the organisation . The organisation ' s first major battle was the Battle of Guadalcanal . Admiral Ghormley ' s Operations Order 1 - 42 established two task forces , Task Force 61 and Task Force 63 , to carry the operation out . On September 20 , 1942 , six weeks after the first American amphibious operation of the war got underway at Guadalcanal , Vice Admiral Aubrey Fitch assumed command of Aircraft , South Pacific Force ( AirSoPac ) . Not a desk - bound admiral , he carried out numerous , hazardous flights into the combat zones , inspecting air activities and bases for projected operations . For these , he received a Distinguished Flying Cross . Under Fitch ' s command , AirSoPac — ultimately encompassing not only Navy but Army , Marine Corps , and Royal New Zealand Air Force air units — achieved great success in aiding the Allied campaign in the South Pacific Area . Commander , Aircraft , Solomons ( ComAirSols ) , directed the combat operations of all land - based air in the Solomons during CARTWHEEL , under the direction of AirSoPac . Rear Admiral Charles P . Mason was the first officer to hold the title ComAirSols ; he assumed command on 15 February 1943 at Guadalcanal . Actually , Mason took over a going concern , as he relieved Brigadier General Francis P . Mulcahy , who had controlled all aircraft stationed at the island during the final phase of its defense . Mulcahy , who became Mason ' s chief of staff , was also Commanding General , 2d Marine Aircraft Wing . The fact that a general headed the staff of an admiral is perhaps the best indication of the multiservice nature of AirSols operations . Vice Admiral Finch retained two areas of flight operations under his direct control ; sea search by long range Navy patrol planes and Army bombers , and transport operations by South Pacific Combat Air Transport Command ( SCAT ) . Throughout its long and useful life ( November 1942 - February 1945 ) , SCAT ' s complement of Marine and Army transports was headed by MAG - 25 ' s commanding officer . SCAT ' s operations area moved northward with the fighting during 1943 , and by August ' s end , all regularly scheduled flights in SoPac ' s rear areas were being handled by the Naval Air Transport Service ( NATS ) .