In April 1944, Ramirez de Arellano was named commanding officer of . He participated in his boat's war patrols 5, 6 and 7. On July 5, 1944, Ramirez de Arellano led the rescue of three downed wavy pilots in the Palau area. On December 4, 1944, "Balao" departed from Pearl Harbor to patrol in the Yellow Sea. "Balao" engaged and sunk the Japanese cargo ship "Daigo Maru" on January 8, 1945. Ramirez de Arellano was awarded a Bronze Star Medal with Combat V and a Letter of Commendation.