The success of the Juneau raid at Rashin on 11 July convinced Vice Admiral Joy that a more substantial raiding party would help to relieve some of the pressure on the Pusan Perimeter. He met with his expert on amphibious warfare, Rear Admiral James H. Doyle, commander of Amphibious Group 1, and directed that a raiding party be assembled to interdict the enemy’s supply. The immediate problem faced by Doyle was to find trained personnel capable of such missions. Doyle knew that he had at least one officer who would qualify. A mobile training team under the command of Marine Major Edward P. Dupras was stationed at Camp McGill, Japan. The team had been engaged in the preparation of U. S. 8th Army regiments for amphibious training exercises.