In 1763, Tronjoli commanded the frigate Licorne, cruising off Newfoundland and Saint-Pierre, before returning to Brest.
[6] In 1768, he commanded the 32-gun frigate Enjouée and sailed from Newfoundland to Morocco to test marine chronometers by Pierre Le Roy and John Harrison one against the other, as part of the quest for an accurate measurement of longitude.
[7] In 1770, Tronjoli was tasked with ferrying troops between Martinique and France, with the 64-gun Union and the fluyt Seine.
[13] He also conducted reconnaissance of the port of Trincomalee, which he reported as a good harbour, but with poor infrastructure and defences, and therefore of little practical interest for naval operations.
[14] Tronjoli twice wrote to the Navy Minister to warn of his lack of resources to carry out his missions against the British,[15] and failing to get reinforcements, fell back to commerce raiding.