At 10am on 13 December 1804, the frigate HMS Princess Charlotte was four leagues west of Cape Antonio when she sighted an unknown brig.

Gardner of Princess Charlotte described Regulus as "a very fine Vessel" that "sails remarkably well" and is "perfectly adapted for His Majesty's Service".

Industry, Galt, master, had sailed from Port Royal on 2 April for Dublin with the fleet, but a French privateer had captured her on the 6th and taken most of her crew and some valuable articles.

[4] On 3 June Morne Fortunee drove the Spanish letter of marque schooner Aimable Jenette ashore between Saona Island and Cape Euganna.

[5] In November Lloyd's List reported that Morne Fortunee had detained Attempt, of and from Salem, Massachusetts, which had been sailing to Martinique with naval stores.

[9] On 8 July Rorie observed a Spanish privateer schooner near Point Tunacas and after a chase of about three hours, succeeded in driving on shore.

After a chase of 24 hours, Morne Fortunee captured Santo Christo, a letter of marque armed with one long 12-pounder and with 15 men on board.

[10] On 27 March the boats of Morne Fortunee joined those of Ulysses, Castor, and Hippomenes in an attempt to cut out the 16-gun French brig Griffon at Marin, Martinique.

[1] They succeeded in capturing a battery but were driven back empty handed, having suffered heavy casualties from the brig's fire.

[12] On 12 December Morne Fortunee, again under the command of Lieutenant John Brown, discovered the French 16-gun brig Cygne and two schooners off the Pearl Rock, Saint-Pierre, Martinique.

Morne Fortunee joined the frigate HMS Circe, the ship-sloop Stork, the brig-sloop Epervier, and the advice boat Express in an action against the squadron.

[14] Morne Fortunee shared with Captain, Pompee, and Amaranthe in the prize money pool of £772 3s 3d for the capture of Frederick on 30 December 1808.