Doug Wean was born on March 29, 1948, in Illinois. He enlisted in the U.S. Navy on August 1, 1966, completed basic training at NTC Great Lakes, Illinois, in October 1966, and completed U.S. Navy Hospital Corps School and Field Medical Service School in April 1967. His first assignment was as a Hospital Corpsman at the U.S. Naval Hospital, Portsmouth, Virginia, from April to October 1967, followed by Marine Corps Counter-Guerrilla Warfare and Jungle Training on Okinawa from October to November 1967. HM3 Wean remained on Okinawa with A Company, 5th Medical Battalion, 26th Marine Regiment of the 9th Marine Amphibious Brigade from November 1967 to January 1968, and then served as a Corpsman with A Company, 5th Anti-Tank Battalion of the 9th Marine Amphibious Brigade on Okinawa and then deployed to South Vietnam from January to June 1968. His next assignment was as a Corpsman with K Battery, 4th Battalion, 12th Marine Regiment of the 9th Marine Amphibious Brigade in South Vietnam from June 1968 until he returned to the United States in January 1969. While in Vietnam, he served during the Tet Offensive and Tet Counter-Offensive in early 1968, Operation Buffalo, Operation Thor, Operation Lancaster II, Operation Scotland II, and Operation Dual Blade V in the Northern I Corps area along the DMZ. He was wounded in action on July 6, 1968, during the battle of at Con-Thien, and again on September 19, 1968, at the Marine outpost called the Rockpile. HM2 Wean served on the staff at the U.S. Naval Hospital, Great Lakes, Illinois, from January to July 1969, and then served with NATO Forces, U.S. Navy Security Group Activity in Edzell, Scotland, as part of the Embassy Staff for Great Britain from August 1969 to February 1971. He received an honorable discharge from the U.S. Navy on February 2, 1971.

His Silver Star Citation reads:

For conspicuous gallantry and intrepidity in action while serving as a Corpsman with Battery K, Fourth Battalion, Twelfth Marines, Ninth Marine Amphibious Brigade in connection with operations against the enemy in the Republic of Vietnam. On the morning of 19 September 1968, while occupying a fire support position at the Rockpile in Quang Tri Province, Petty Officer Wean's platoon came under a heavy volume of North Vietnamese artillery and small arms fire. During the ensuing attack, several rounds impacted int he powder storage area wounding numerous Marines and igniting an intense fire that spread through out the platoon area. Responding instantly to a call for medical assistance, Petty Officer Wean unhesitatingly left his position of cover and rushed across the fire-swept terrain to the side of a wounded comrade. Ignoring the fragmentation of exploding ordinance and the enemy small arms fire aimed at and impacting near him, he shielded the wounded Marine with his own body while calmly administering medical care to the casualty. When the wounded Marine was evacuated from the field of fire, Petty Officer Wean fearlessly moved to another wounded casualty and skillfully treated his wounds, until he was extracted from the combat area. His heroic actions and sincere concern for the welfare of his comrades, inspired all who observed him and was instrumental in saving the lives of two Marines. By his courage, resolute determination and steadfast devotion to duty in the face of great personal danger, Petty Officer Wean upheld the highest traditions of the United States Marine Corps and of the United States Naval Service.