Quérangal joined the Navy in 1775, rising to lieutenant by 1790. In 1791, he was sent to Saint-Domingue, where he captained a schooner and a brig, and was tasked with secret missions. Sent back to Nantes, he was briefly arrested. He went to Paris, and resigned his commission in reaction to the Execution of Louis XVI. On the advice of Gaspard Monge, then Ministre de la Marine, he joined back and was sent to Brest. There, he had to fight a number of accusations; he was eventually sent to Lorient by Jean Bon Saint-André, where was made first officer of "Tyrannicide". He was later given command of the fluyt "Ville de Lorient", but was shortly arrested again, and detained for nine months.