At first employed in Paris in reorganising the navy, then in inspecting mainland France's ports, in 1801 he was put back into active service, at first on the ship of the line "Océan", then on the "Mont-Blanc", the latter of which was part of the naval force under admiral Villaret for the Saint-Domingue expedition. Put in command of four ships of the line and two frigates and ordered to capture fort Dauphin, Magon did so so quickly and successfully that the expedition's supreme commander Leclerc immediately promoted him to contre-amiral, stating in his report "This nomination was on the army's unanimous wish, and I do not doubt that the government will confirm it" (as it did so in March 1802).