He started his military career as a sub-lieutenant in the Régiment de Normandie en 1745, and rose to Lieutenant.

[1] From 1766 to 1775, Cheyron worked on naval tactics and signals, and he was made a Knight in the Order of Saint Louis in 1771.

On 25 March 1773, he presented a memorandum to the Court, titled Mémoire sur la tactique navale — Signaux de nuit et pour le temps de brume pour l'escadre du Roi.

[3] In 1775, he was brigade chief of the Gardes-Marine in Rochefort, and became major of the training squadron (escadre d'évolution) in 1776.

In July 1778, Cheyron was appointed to Orvilliers' squadron, and he applied his techniques during the Battle of Ushant.