The French brig Observateur, which was launched in 1800 for the French Navy, was a Vigilant-class 16-gun brig, one of six built to a design by Pierre-Alexandre-Laurent Forfait. The Royal Navy captured her in 1806 and took her into service as HMS Observateur. She participated in two actions, one for the French Navy and one for the Royal Navy, and one campaign before she was laid up in 1810. The Navy did not succeed in selling her until 1814.
French service
The French Navy commissioned Observateur in 1802 and by 4 October 1802 she was under the command of lieutenant de vaisseau Bonamy, having sailed from Havre to Newfoundland protecting French fisherman, and then returning to Brest. Then between 8 April 1803 and 13 September, still under the command of Bonamy, by now a capitaine de frégate, Observateur returned from Saint-Domingue to Brest, cruised to the region around Santa Maria Island, and then returned to Corogne, finishing at Ferrol.
On 28 January 1806 Observateur was under the command of Lieutenant de vaisseau Jean Croizė and part of the Ferrol squadron. She sailed with the combined fleet from Ferrol to Cadiz. Then between 1 March and 4 April, Observateur sailed from Cadiz to Cayenne. She was in company with her sister-ship Argus, under the command of Lieutenant de vaisseau Yves-François Taillard, the senior commander. On 3 March they encountered a British corvette in the Atlantic. Argus was eager to escape and abandoned Observateur.
Observateur sailed less well and a single-ship action ensued, during which she suffered several casualties, both dead and wounded. Neither side was able to prevail, and though Observateur lost her bowsprit while attempting to board the British vessel, the British vessel did not pursue her advantage that evening. Next morning combat resumed, but at a distance and the British vessel withdrew, freeing Observateur to make for Santa Cruz de Tenerife. Although Observateur was unable to determine the name of her adversary, despite retaining a British flag that had somehow fallen aboard during the boarding attempt, Croizé was able to determine that she was a three-master armed with 26 guns. On 6 March, as Observateur approached the port a British lugger approached and a new engagement ensued. Fortunately, the governor of Teneriffe sent out another brig and two schooners to chase the lugger off and escort Observateur to safety. Observateur spent 40 days there refitting before she sailed again for Cayenne where she met up again with Argus.
Capture
On 9 June 1806 the frigate , in company with , captured Observateur after a chase and a slight exchange of gunfire. Observateur, of 16 guns, though pierced for 20, had a crew of 104. She had left Cayenne on 15 March provisioned for a cruise of four months and in company with the French brig Argus, but had not taken anything. Several days prior to the engagement Croizé had taken ill; he had, therefore, relinquished command to his second-in-command, enseigne de vaisseau Robert-Henri Debernes. One problem confronting Observateur was that although she carried four British 12-pounder carronades in addition to her twelve 4-pounder guns, the only shot she had for the 12-pounders were actually for 8-pounders.
British service
The Royal Navy immediately took her into service as HMS Observateur. Admiral John Poer Beresford, chief of the Halifax station, wrote that the officers of the yard there spoke so highly of Observateur that he commissioned her there under Lieutenant the Honourable George Alfred Crofton (acting). Beresford gave Crofton a complete crew of officers and men and instructed him to sail to Bermuda to search for Argus.
Venelia, Eldridge, master, arrived at Bermuda on 19 July 1806. She had been sailing from New York to Martinique when Observateur detained her. A week later the American vessel Huntress, Dodge, master, arrived at Bermuda also. She had been sailing from New York to New Orleans when Observateur detained her. Lastly, in December, Observateur detained and sent into Bermuda Eliza, Gardner, master, which had been sailing from Cap Francois to Saint Bartholomew.
In February 1807 Commander William Love replaced Crofton. However, on 17 December Observateur was under the command of Commander Charles Claridge when she captured Mars.
In January 1808 Lieutenant John Lawrence took command; he received his promotion to Commander in March. Later that year Commander Richard Smith replaced Lawrence.