Kammala wannan magana: A lokacin da aka fara yakin Anglo-Faransa a 1778, Grenier yana aiki a kan "Sphinx" mai bindigogi 64. Ya shiga cikin yakin Ushant, sannan aka ba shi umurnin jirgin ruwa na "Boudeuse" a cikin rundunar karkashin Estaing. A ranar 22 ga Janairu, 1779, ya kama jirgin ruwan Burtaniya mai suna "Weazle". Ya shiga cikin yakin Grenada da kuma a cikin
Siege na Savannah a watan Satumba na shekara ta 1779. A shekara ta 1780, yana kan aikin rakiyar jirgi. An ba Grenier girma zuwa Kyaftin a ranar 9 ga Mayu, 1781, kuma ya yi aiki a kan "Bretagne". Sa'an nan kuma ya yi aiki a kan kayayyaki ga rundunar Guichen.