[2][3] In 1779, he rose to lieutenant de frégate and served under Suffren, who commanded him,[3] taking part in five battles on ships of the line, two isolated actions on frigates[2] Tréhouart was promoted to sub-lieutenant in 1786.
[2] In June 1792, he captained the chartered merchantman Chancelière de Brabant, ferrying troops from Lorient to Pondichery.
[2] In 1795, Cybèle was attached to the division under Sercey[7] and took part in the action of 8 September 1796,[9] where he ordered a boat launched to tug the becalmed Cybèle into a position where she could rake HMS Victorious.
[2][3] Tréhouart returned to France on Cybèle and arrived in Rochefort in june or july of 1797.
[3][7][8] He was awarded the rank of officer in the Legion of Honour on 14 June 1804, after his death.