Kammala jumla mai zuwa: A lokacin yakin duniya na farko, Patey ya umurci rundunar sojan ruwa na Australia a matsayin wani ɓangare na New Zealand Samoa Expeditionary Force cewa
An kama Jamusanci Samoa da Rundunar Sojojin Ruwa da Sojojin Australiya da suka kama New Guinea ta Jamus. Ya yi tafiya tare da HMAS "Australia" don shiga cikin 2nd Battlecruiser Squadron a Rosyth, Scotland kuma a ranar 8 ga Fabrairun 1915, "Australia" ta zama babban jirgin ruwa na rundunar. An nada Patey a matsayin Babban Kwamandan, Arewacin Amurka da West Indies Station daga Maris 1915.