Turpin had started sailing at the age of 14 on the FIDELE vessel, commanded by his uncle Admiral Jean-Baptiste Mac Némara, (who had married a young lady Turpin de Jouhé), from a large Irish family.
Turpin joined the Navy as a Garde-Marine on 11 February 1751.[3] In 1753, he commanded the 20-gun xebec Caméléon, sailing from Rochefort to Saint-Domingue and Louisiana.[4] He returned in 1754.[5]
Turpin was promoted to Lieutenant on 1 October 1764.[3] In 1773, he commanded the 12-gun corvette Écureuil, and sailed from Brest to Martinique.[6] He then continued to the Windward Islands.[7]
Turpin was promoted to Captain on 4 April 1777.[3] The year after, he captained the 60-gun Fier,[8] part of the First Division of the Blue squadron in the fleet under Orvilliers.[9][1] He took an incidental part in the Battle of Ushant on 27 July 1778, although Fier was so underpowered compared to the other ships of the line that she remained outside the line of battle, with the frigates.[10]
Turpin captained Fier at the Capture of Grenada on 3 July 1779.[11] On 16 August 1779, Fier was damaged in a gale, losing her mainmast, her mizzen and her fore-topmast, and had to anchor at Martinique to effect repairs.[12]