Hermes was re-engined and lengthen in 1842, Megaera was wrecked in Jamaica in 1843. the remaining vessels served on many different stations of the Empire.

Acheron was the second named vessel since it was used for an 8-gun Bomb, purchased in October 1803 then captured by the French in the Mediterranean and burnt on 3 February 1805.

[1] Hermes was the sixth named vessel since it was used for a 12-gun brig sloop, captured from the Dutch (Mercurius) by Sylph at Texel on 12 May 1596 and foundered in January 1797.

[2] Megaera was the second named vessel since it was used for a 14-gun Fireship, launched by Teague of Ipswich in May 1783 and sold to J. Darkin on 3 April 1817.

Her depth of hold increased to 18 feet 2 inches (5.54 metres) with her builder's measured tonnage calculated at 827 88/94 tons.

All four ships were initially armed with two 9-pounder (13 1/2 hundredweight (cwt)) (muzzle-loading smooth bore MLSB) brass guns.