Copeman served in
cruisers and
destroyers in both the
Atlantic and
Pacific Fleets. His first assignment was as Electrical officer and Main Propulsion assistant in . His second division officer tour was as a gas turbine inspector for Pacific Fleet Propulsion Examining Board. Following graduation from Surface Warfare Officers School Department Head Course in 1987, he reported as the commissioning engineer officer in and participated in combat operations in the Persian
Gulf War while assigned in her. Subsequent sea tours include executive officer in and as commanding officer . Following a tour as fleet operations officer in
2nd Fleet, Copeman commanded
Destroyer Squadron 28, where he deployed, as the Sea Combat commander, in the
George Washington Carrier Strike Group to the
Persian Gulf in support of
Operation Iraqi Freedom and
Operation Enduring Freedom. While ashore, Copeman served in the
U.S. Strategic Command,
Omaha, Nebraska, as an action officer in the Current Operations Directorate (J31). His next shore tour was as a BMC4I requirements officer in the Theater Air Warfare Branch in the Surface Warfare Directorate (N76),
Office of the Chief of Naval Operations. He served as executive assistant to the deputy commander and chief of staff, U.S. Atlantic Fleet, the director of Navy Senate Liaison in the
Office of Legislative Affairs and the chief of staff for Naval Surface Forces, San Diego, California. He served as deputy chief of staff for operations and training for the U.S. Pacific Fleet. He then served as commander,
Joint Task Force, Guantanamo Bay, Cuba, followed by a period as chief of legislative affairs. He retired from the Navy on 1 October 2014. ==Awards and honors==