In the 18th century and most of the 19th, a sloop-of-war in the Royal Navy was a warship with a single gun deck that carried up to eighteen guns. The rating system covered all vessels with 20 guns and above; thus, the term sloop-of-war encompassed all the unrated combat vessels, including the very small gun-brigs and cutters. In technical terms, even the more specialised bomb vessels and fireships were classed as sloops-of-war, and in practice these were employed in the sloop role when not carrying out their specialised functions.
The following ships of the Royal Navy were assigned the name Calypso, after Calypso, a sea nymph in Greek mythology:
HMS Apollo, the fourth ship of the Royal Navy to be named for the Greek god Apollo, was a fifth-rate frigate of a nominal 36 guns. She was the name ship of the Apollo-class frigates. Apollo was launched in 1799, and wrecked with heavy loss of life in 1804.
HMS Fly was a Swan-class ship sloop of the Royal Navy, launched on 14 September 1776. She performed mainly convoy escort duties during the French Revolutionary Wars, though she did capture three privateers. She foundered and was lost with all hands early in 1802.
HMS Martin was a 16-gun sloop of the Royal Navy. She served at the Battle of Camperdown in 1797 and captured two privateers before she disappeared in 1800.
HMS Wasp was an 18-gun sloop of the British Royal Navy. She was formerly the French naval brig Guêpe, which the Navy captured in 1800. She served during the French Revolutionary and Napoleonic Wars, and was sold out of naval service in 1811.
Hortense was a 40-gun Hortense-class frigate and lead vessel of her class of the French Navy.
Iphigénie was a 32-gun Iphigénie-class frigate of the French Navy, and the lead ship of her class. She was briefly in British hands after the Anglo-Spanish capture of Toulon in August 1793 but the French recaptured her December. The Spanish captured her in 1795 and her subsequent fate is unknown.
HMS Nemesis was a 28-gun Enterprise-class sixth-rate frigate of the Royal Navy. The French captured her in 1795 at Smyrna, but in 1796 a squadron led by Barfleur brought her out of the neutral port of Tunis. Throughout her career she served under a number of commanders who would go on to have distinguished careers. She was converted to a troopship in 1812 and was sold in 1814.
San Fermín was launched in 1779 and became an armed merchant corvette for the Gipuzkoan Trading Company of Caracas. The British captured her at the action of 8 January 1780 and took her into the Royal Navy as HMS St. Fermin. The Spanish Navy recaptured her in 1781 and put her into service with the same name until she was decommissioned in 1785.
HMS Sprightly was a 10-gun cutter of the Royal Navy, built to a design by John Williams, and the name ship of her two-vessel class of cutters. She was launched in 1778. The French captured and scuttled her off the Andulasian coast in 1801.
HMS Galgo was a Jamaican privateer that the Spanish Navy captured in 1797 and named Galgo Inglés, and that the British captured in November 1799. In her brief career she detained, took, or destroyed a number of small prizes before October 1800, when she foundered, with the loss of most of her crew and passengers.
Etna was a French naval Etna-class ship-sloop launched in 1795 that the Royal Navy captured in November 1796. She was taken into service as HMS Aetna and renamed to HMS Cormorant the next year. She captured several merchant vessels and privateers before she was wrecked in 1800 off the coast of Egypt.
The Dutch ship sloop Havik was launched in 1784 and served in the Batavian Navy. The British captured her in 1796 at the capitulation of Saldanha Bay. She then served briefly in the Royal Navy as HMS Havick before she was wrecked in late 1800.
HMS Rattler was a 16-gun sloop of the Royal Navy. Launched in March 1783, she saw service in the Leeward Islands and Nova Scotia before being paid off in 1792 and sold to whaling company Samuel Enderby & Sons. She made two voyages as a whaler and two as a slave ship before she was condemned in the Americas as unseaworthy in 1802. She returned to service though, sailing as a whaler in the northern whale fishery, sailing out of Leith. She continued whaling until ice crushed her in June 1830.
HMS Barbuda was commissioned into the Royal Navy in 1780 after having briefly served as an American privateer. Barbuda was one of the two sloops that captured Demerara and Essequibo in 1781, but the French Navy captured her there in 1782 and took her into service as Barboude. The French Navy sold her to private owners in 1786, and she served briefly as a privateer in early 1793 before the French Navy purchased her again and named her Légère. She served them until mid-1796 when the Royal Navy captured her and took her into service as HMS Legere. She was wrecked off the coast of Colombia, without loss of life, in February 1801.
HMS Vautour was 16-gun brig-sloop of the British Royal Navy. The navy captured her from the French on the stocks in 1809 and commissioned her in 1810. She foundered in October 1813.
HMS Dolphin was a 44-gun fifth rate ship of the Royal Navy launched in 1781. Designed by Sir Thomas Slade, she carried her armament on two decks and had a main battery of 18-pound long guns. She made an appearance at the Battle of Dogger Bank in 1781. The rest of her 36-year career was uneventful, much of it being spent as a transport or hospital ship, armed only with twenty or twenty-four, 9-pounders. She was broken up at Portsmouth in 1817.
HMS Busy was launched in 1797 as the only member of her class of brig-sloops. She captured one French privateer and numerous small merchantmen, but spent most of her career escorting convoys to and from the West Indies. She foundered in 1806 while serving on the Halifax, Nova Scotia, station.
HMS Resistance was a 44-gun fifth-rate Roebuck-class ship of the Royal Navy launched in 1782. Based on the design of HMS Roebuck, the class was built for use off the coast of North America during the American Revolutionary War. Commissioned by Captain James King, Resistance served on the West Indies Station for the rest of the war. She captured the 24-gun corvette La Coquette on 2 March 1783 and then went on in the same day to participate in the unsuccessful Battle of Grand Turk alongside Horatio Nelson. Resistance then went for a refit in Jamaica, during which time King fell ill and was replaced by Captain Edward O'Bryen. O'Bryen commanded Resistance until March 1784 when she was paid off. In 1791 she was recommissioned as a troop ship, but was converted back into a warship in 1793 at the start of the French Revolutionary War, under Captain Edward Pakenham.
United Kingdom 
