He was then named head of internal and security service on the battleship Dunkerque and his work aboard ship was officially deemed satisfactory.

He then got himself noticed at the time of Opération Vado (which involved bombarding the port at Genoa) and was thus cited for his sang-froid (roughly, calmness in the face of danger) and his tactical skill.

After becoming captain ("capitaine de vaisseau") in July 1941, Jaujard was first second-in-command on the general staff of Southern Maritime Forces at Algiers.

By March of the same year, he had risen to rear admiral (contre-amiral), and two months later, he was commanding the IV Cruiser Division, and he took part in the Normandy landings on D-Day (6 June 1944), successfully bombarding the German positions at Port-en-Bessin.

While in command of the so-called Flank Force, a unit that brought together cruisers and fighter aircraft, he supported Allied armies' progress on the Italian coast.

Jaujard was transferred to the "second section" (for French officers no longer on active duty, but still kept at the armed forces minister's disposal should they be needed) in April 1956.