 In the early 1970s, Rinn served as a counterinsurgency adviser and military training officer along the Mekong River and was involved in combat operations along the upper reaches of the Mekong River.In 1975, he was the Weapons Officer on USS Blakey FF 1072 a and deployed to the Mediterranean for six months.From 1976 through 1979, he served as Operations and Tactics Officer in the First Canadian Destroyer Squadron operating in the North Atlantic and Mediterranean sea.