For heroic achievement in connection with combat operations against the enemy in the Republic of Vietnam while serving as a corpsman with Company I, Third Battalion, Ninth Marines, Third Marine Division. On 27 July 1968, Company I was preparing a night defensive position during a search and destroy operation north of the Dong Ha Combat Base. Suddenly, the Marines came under an intense hostile mortar attack and sustained one serious casualty. With complete disregard for his own safety, Petty Officer Walriven unhesitatingly left his covered position and rushed across an open area to the side of the wounded Marine. Determining that the man would require immediate first aid, Petty Officer Walriven fearlessly ignored the enemy mortar rounds impacting near him as he steadfastly remained in the hazardous area and treated his patient. His heroic and timely actions inspired all who observed him and resulted in vital medical care being provided to a seriously injured Marine. Petty Officer Walriven’s courage, sincere concern for the welfare of his comrade and unwavering devotion to duty at great personal risk were in keeping with the highest traditions of the Marine Corps and the United States Naval Service.