Frederick Lewis Maitland took command of "Vengeur" in October 1818, and in 1819 sailed her to South America. He took Lord George Beresford from Rio de Janeiro to Lisbon in 1820, and then returned to the Mediterranean. He then carried Ferdinand I, King of the Two Sicilies from Naples to Livorno, on his way to attend the Congress of Laibach (modern Ljubljana). The passage was rough and lasted seven days, but they arrived safely on 20 December. After His Majesty landed, he personally invested Maitland with the insignia of a knight-commander of the order of St. Ferdinand and of Merit, and gave him a gold box with the king's portrait set in diamonds. Maitland and "Vengeur" then returned to England, arriving at Spithead on 29 March 1821. "Vengeur" was found to be defective and was paid off on 18 May 1821 at Sheerness.