Marc began his Naval career when he was commissioned in June 1968 as an ensign in the U.S. Navy and was designated a Naval Aviator in July 1969. During his active duty career, he made deployments to Vietnam, the Mediterranean as well as to the Persian Gulf, Norwegian and Black Seas. He is a combat veteran of Vietnam and Desert Shield/Storm and flew helicopters on combat search and rescue, special operations missions, anti-submarine warfare and logistics support missions.
He has worked with the armed forces of Australia, Canada, Japan, Thailand, Republic of Korea, the Philippines and the U.K. In 1991, he was recalled for Desert Shield and Desert Storm and during that conflict, was responsible for the operational tasking and employment of 140 helicopters from 14 nations as well as special operations forces assigned to the Persian Gulf Battle Force.