April 1805, she arrived off Derna to participate in the attack, capture, and occupation of that town. She remained until 17 May, during which time she provided cover for the forces of Hamet Caramanli, former Bashaw of Tripoli, as they went into action against the army of Hamet's brother Yusuf ibn Ali Karamanli, who had overthrown Hamet and assumed his title. Departing on the 17th, Nautilus retired to Malta with dispatches and casualties. At the end of the month, she returned to Tripoli and on 10 June hostilities ceased with the signing of a peace treaty. Nautilus remained in the Mediterranean for a year after the treaty went into effect, conducting operations from Malta and Gibraltar. In the spring of 1806 she was assigned to Algiers for dispatch duty, sailing in June for the United States. Between wars Arriving at Washington, D.C., in mid-July, Nautilus entered the Washington Navy Yard there and was placed in ordinary. Reactivated in 1808, she was employed on the East Coast until entering the Navy Yard again in 1810. The Navy then altered her to a brig, giving her a battery of twelve 18-pounder (8 kg) carronades. The Navy recommissioned Nautilus in 1811 and she joined Stephen Decatur's squadron. Capture After the War of 1812 with Britain broke out on 18 June 1812, Nautilus gained the dubious distinction of being the first vessel lost on either side. A squadron built around the Third Rate (64 guns) and the two Fifth Rate frigates, (38 guns) and (32 guns), captured her off northern New Jersey. Nautilus was 24 hours out on a cruise from New York when Shannon and Aeolus captured her on 17 July. At the time of her capture she mounted 16 guns, had crew of 106 men and was under the command of Lieutenant William M. Crane. HMS Emulous The British immediately but informally took Nautilus into service under the name Emulous, having just lost the on 2 August. On 29 August the Admiralty formally purchased Nautilus/Emulous for £3,252 17s 2d. On 2 February 1813 Emulous was commissioned under Commander William Mackenzie Godfrey, on the Halifax station. Emulous proceeded to capture a number of American privateers or merchant vessels listed below: On 25 August 1812, Emulous captured the American ship Gossamer. That same day, Emulous captured the American privateer schooner Science, under the command of Captain W. Fernald. Science, of 74 tons, five guns,