Kammala wannan jumla: Masters ya koma Pearl Harbor don shiga cikin 10th Defense Battalion a watan Nuwambar 1942. Daga baya, a matsayin jami'in zartarwa na rundunar, wanda aka ba shi zuwa ga I Marine Amphibious Corps, ya yi aiki a cikin
Tsibirin Solomon da Russell. An ba shi mukamin Laftanar Kanal a watan Afrilun 1943. A watan Agusta na wannan shekarar, ya umurci 2nd Battalion 1st Marines a takaice a Ostiraliya kafin ya sake dawo da rukunin daga Disamba 1943 zuwa Fabrairu 1944 a yakin Cape Gloucester, a karkashin umarnin Rupertus, yanzu babban kwamandan rundunar sojan ruwa ta 1.