In September 1793, Rousseau ranked enseigne de vaisseau non entretenu, and was in command of the aviso Espérance.
In the summer of 1804, Rousseau was in command of the gunboat Etna, stationed in Le Havre, and tasked with escort duties.
[12] On 20 June, the 74-gun Duguesclin was launched at Antwerp, and Rousseau was tasked to sail her on the Escaut River to Vlissingen.
The cannonade attracted the attention of the frigates HMS Latona and Horatio, who gave chase and started the action of 10 February 1809.
Rousseau was shot through the chest, and relinquished command of Junon to Lieutenant Jean-Léon Émeric.