Gunner's Mate (Guns) First Class Hugh Robert Harnlee begins his rise in the US navy following a turret fire on the USS Wilmington on the gun line off the coast of Vietnam in 1970. On the Gun Line charts the early phase of Harnlee's career, a period which includes changes in the navy itself. WWII ships are being replaced, so is the weaponry and the personnel. With anti-war sentiments rising ashore, together with racial tension and the introduction of female crew, it takes a special officer, the likes of Harnlee, to steer the service to calmer seas. From the brown waters off the coast of Vietnam to the undersea tension of the Cold War, On the Gun Line is an absorbing and technically faithful account of the US navy at war.