After the British attack on Copenhagen in 1807 and the outbreak of the Gunboat War between Britain and the Dano-Norwegian kingdom, he took a small Danish vessel, the "Admiral Juul", and in the action of 2 March 1808 engaged HMS "Sappho"; the British captured the "Admiral Juul" and treated Jørgensen as a privateer. In 1809, while in England on parole, he suggested to a merchant that a voyage to Iceland could be profitable as the island was suffering from food shortages at the time, due to the Danish monopoly on Icelandic trade. Jørgensen accompanied the voyage of the "Clarence" as an interpreter. That voyage failed to trade any goods as the ship was British and Denmark had forbidden trade with Britain. Shortly thereafter, "Rover" arrived at Reykjavík. The Board of Admiralty had sent it to prepare the way for a second British merchant voyage.