Sartorius went on to command Malabar in the Mediterranean Fleet and received on board Baldomero Espartero, the regent of Spain, who had been driven out by a coup d'état.

Between May 1802 and October 1804 he served aboard the frigates Fisgard and Naiad, commanded by Captain James Wallis on the Home Station, and was rated as a midshipman.

There he was employed in protecting to the Greenland fisheries, before being sent to the Mediterranean Fleet, where he assisted at the reduction of the Phlegraean Islands of Ischia and Procida in June 1809, and operated in the defence of Sicily against the threatened invasion of Joachim Murat.

[5] On 4 April 1810, Sartorius commanded the boats of the Success and brig Espoir, at the destruction of two vessels laden with oil, while under a heavy fire, on the beach near Castiglione,[6] and on the 25th he assisted at the capture of an armed ship and three barques close to the castle of Terracina.

[5] After serving with the flotilla at the defence of Cádiz he was promoted to commander on 1 February 1812, and was appointed to the gun-brig Snap in August 1812, and then the brig-sloop Avon in July 1813, both on the Home Station.

[5] Promoted to post-captain on 6 June 1814, Sartorius commanded the 20-gun Slaney from December 1814 until August 1815, and was present at the surrender of Napoleon Bonaparte to Captain Frederick Maitland of Bellerophon at Rochefort on 15 July 1815.

He later received the thanks of the President and Congress of the United States for his efforts in saving the frigate USS Missouri, which caught fire at Gibraltar in August 1843.

[4] Malabar was paid off in 1844,[5] and Sartorius saw no further service at sea,[4] though he continued to take an active interest in naval affairs, becoming one of the earliest advocates of ram ships.