In the year VI (from 22 September 1797 to 21 September 1798), Dumanoir contributed to the preparations for the departure of the fleet for the Egyptian campaign. On 19th May 1798, the fleet left Toulon under the command of Vice-Admiral Brueys d'Aigalliers. Rear Admiral Gantheaume was the major-general of the squadron. Three other Rear Admirals commanded the divisions of the fleet: Blanquet du Chayla led the vanguard; Villeneuve, the rearguard; Decrès, the light squadron. Dumanoir boarded the ship "Dubois" and was in charge of the direction of the convoy attached to the army.