In mid-1942, Japanese forces invaded Guadalcanal. Vouza returned to active duty with the British forces and volunteered to work with the Coastwatchers. A Scotsman, Major Martin Clemens, a former British Solomon Islands Protectorate District Officer, was the officer in charge of SgtMaj Vouza's brigade of native scouts. Vouza's ability as a scout had already been established when the US 1st Marine Division landed on Guadalcanal on 7 August 1942. That same day, Vouza rescued an aviator from USS "Wasp" who was shot down in Japanese-held territory. He guided the pilot to American lines, where he met the Marines for the first time.