In September 1915, assigned to the intelligence service established in an island in the Levantine Mediterranean, he organized a network covering the entire Levant.

He was appointed to command the destroyer La Palme in the Mediterranean in 1929, Capitaine de frigate in April 1930, he was tasked to manage and run the application school of the enseignes de vaisseau embarked on board the 1st Light Division which replaced in provision the Jeanne-d'Arc and conducted accordingly a long campaign on the African coasts, Antilles and the Mediterranean.

At Vichy, the counter-admiral Auphan was part of the tenant groups which harbored a political view of attentisme (the act of waiting and refraining until situations become more clear and precise).

State Secretary of the Navy (French: Secrétaire d'État à la Marine) as of April 1942, he opposed the demanding German requirements related to materials of merchant tonnage.

Along with French Army general Maxime Weygand, he assumed a staunch position of opposition to the politics of collaboration at the corps of the government.

Auphan dedicated his life later to writings: a close figure to General Maxime Weygand or Colonel Rémy, he published his memoirs, defended his views and remained loyal to the memories of Marshal Philippe Pétain.