His Majesty's hired armed brig Louisa served the British Royal Navy under contract from 25 May 1799 to 13 November 1801.
She was the former mercantile brig Gambier, of 18492⁄94 tons (bm), and was armed with sixteen 18-pounder carronades.
She was under the command of Lieutenant Banks and was carrying despatches from Admiral Duckworth who reported that in the Straits he had encountered sailing from Carthagena to Lima, the annual fleet with 150 tons of quicksilver.
[7] The privateer, of eight guns and 60 men, is almost certainly the one that Lloyd's List reported the "sloop of war" Louisa, coming from Egypt, taking into Gibraltar on 15 April.
[9] Although apparently her contract had expired, still on 20 January 1802 "the Louisa, of 14 guns, Lieutenant Truscott", left Plymouth with despatches for Malta.