On 4 July, Joy ordered Rear Admiral James H. Doyle, commanding Amphibious Group 1 (and thus TF90) to travel with selected staff members to Tokyo to plan amphibious operations.
His [Rear Admiral James H. Doyle, commanding Amphibious Group 1] command had spent early May 1950 conducting landing exercises in southern California for the benefit of U.S. Army Command and General Staff College observers.[cmdctl-12]
MacArthur had requested that the Navy train his Eighth Army troops in amphibious techniques, and on 20 May Amphibious Group 1 had sailed for Japan, where it had reported to COMNAVFE and was designated Task Force 90. Its only ships were the command ship USS Mount McKinley (AGC 7), the assault transport USS Cavalier (APA 37), the assault cargo ship USS Union (AKA 106), the tank landing ship USS LST 611, and the fleet tug USS Arikara (ATF 98). However, Doyle himself had considerable amphibious experience, and his staff officers were virtually all veterans of World War II’s Central and Southwest Pacific amphibious operations.[cmdctl-13]
12. Commander, Amphibious Group 1 and Northern Attack Force Task Force [hereafter TF] 13, Operation Order 4-50, “Demon III (Satan at San Clemente; Mephisto at Aliso),” Command and General Staff College Demonstration, 11–12 May 1950, OA, NHC.
13. Commander Amphibious Group [hereafter COMPHIBGRU] 1, War Diary, date- time group 240001Z [0001 Greenwich Mean Time, 24 June] June 1950 to 152400Z July 1950, OA, NHC.