William Cooper was a member of the Office of Naval Security and Intelligence serving as a Harbor and River Patrol Boat Captain at Danang and the Dong Ha River Security Group, Cua Viet, Republic of Vietnam. William Cooper was awarded several medals for his leadership and heroism during combat including two with "V" for Valor.

He served on the Intelligence Briefing Team for the Commander In Chief of the Pacific Fleet. William was the Petty Officer of the Watch and designated KL-47 SPECAT operator in the CINCPACFLT Command Center at Makalapa Hawaii. There he held a Top Secret, Q, SI, security clearance.