HMS Mercury was a 28-gun Enterprise-class sixth-rate frigate of the Royal Navy. She was built during the American War of Independence and serving during the later years of that conflict. She continued to serve during the years of peace and had an active career during the French Revolutionary Wars and most of the Napoleonic Wars, until being broken up in 1814.

HMS Spartan was a Royal Navy 38-gun fifth-rate frigate, launched at Rochester in 1806. During the Napoleonic Wars she was active in the Adriatic and in the Ionian Islands. She then moved to the American coast during the War of 1812, where she captured a number of small vessels, including a US Revenue Cutter and a privateer, the Dart. She then returned to the Mediterranean, where she remained for a few years. She went on to serve off the American coast again, and in the Caribbean, before being broken up in 1822.