HMS Lyme was a 28-gun, sixth-rate frigate of the Royal Navy which saw service against France in the Seven Years' War. Principally a hunter of privateers, she was also intended to be a match for contemperaneous French frigates which had shown to be faster and more maneuvreable than their British equivalents. To this end her design was essentially a replica of a captured French vessel Le Tygre, with minor reductions in dimensions and armament. Over twelve years at sea she captured four French privateers and ably contributed to several actions against larger but slower enemy craft. Her record, along with that of her sister ship , provided impetus for the Royal Navy to abandon its overly conservative 1719 Establishment for vessel design, and introduce what would later be known as "true frigates" with a single gundeck and much improved seaworthiness and speed.
Lyme was an oak-built sixth-rate, one of two vessels forming the of frigates.
As with her sister ship she was intended to be a replica of Le Tygre, a 26-gun French privateer captured off Ushant on 22 February 1747. Le Tygres capture had been made by the 50-gun after a three and a half hour chase. The capture coincided with plans by Admiralty to commence a continuous blockade of French Atlantic ports in the final years of the War of the Austrian Succession, which neccesitated the building of vessels capable of overhauling French privateers in all weathers. While a subsequent Admiralty survey of Le Tygre noted her light and poor-quality materials, it emphasised her "great character for sailing" which had aided in prolonging her attempted escape. On considering the survey, the Admiralty Board under George Anson elected to construct two prototype vessels, Lyme and Unicorn to Le Tygres general design.
Lyme was actually completed with 28 guns including four smaller weapons on the quarterdeck, but the latter were not included in the ship's official establishment until 22 September 1756. The new ship had a round bow, a lion figurehead, three-light quarter galleries and six pairs of quarterdeck gunports.
Lyme was named on 2 August 1748, and commissioned in September 1748 under Captain Charles Proby, while still building in Deptford Dockyard under the direction of Master Shipwright John Holland. After her launch, she was fitted out there, finally sailing when completed on 8 February 1752. Her total initial cost had been ã12,282.0.1d (including fitting out costs).
She sailed for the Mediterranean in May 1749. Returning home, she was fitted out at Portsmouth Dockyard from December 1750 to March 1751 (at a cost of ã389.6.9d) for bearing the new ambassador to Tripoli out to the Mediterranean.
After her first commission finished in 1752, she was surveyed on 1 July 1753, and then underwent a small repair and was fitted out at Plymouth Dockyard (under Admiralty Order on 4 December 1753, for a total cost of ã1,519.6.3d) in February to March 1754. She was recommissioned under Captain Samuel Faulkner, but some months later he was replaced by Captain Edward Vernon, under whom the Lyme joined the Western Squadron based in Plymouth. In March 1758 she was under Captain James Baker, in the Mediterranean to 1759.
Back home, and under Vernon's command again, she was surveyed again on 7 June 1760, and then underwent a small repair and was fitted out at Chatham Dockyard (for a total cost of ã4,211.6.4d) in May to August 1760, before sailing for the Baltic.