Sergeant Watt was a member of Headquarters Battery, 555th Field Artillery Battalion, 5th Infantry Regimental Combat Team. He was listed as Missing in Action while fighting the enemy near Pongam-ni, South Korea on 12 August 1950. He was presumed dead on 31 December 1953. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

Watt was awarded the Purple Heart, the Korean Service Medal, the United Nations Service Medal, the National Defense Service Medal, the Korean Presidential Unit Citation and the Republic of Korea War Service Medal.