He met with Admiral Émile Muselier, but was unable to obtain a command at sea. Promoted to "Capitaine de corvette" (lieutenant commander) on 1 October 1940, he joined the Second Office of the Free French Naval Forces and requested to be sent to occupied France. After having convinced General de Gaulle, he received the mission to organise an intelligence network in western France, codenamed "Nemrod", which had been created in September 1940 by Maurice Barlier and Jan Doornik, but lacked coordination and development. He was officially assigned to this task on 15 December 1940.