After fitting out the ship to act as a privateer, Lynch obtained a corsair license from the Buenos Aires Supreme Director José Rondeau.

[2] In doing so, Jewett crossed the line between privateer and pirate, since his corsairs license restricted his activities to Spanish ships (the United Provinces of the River Plate were not at war with Portugal).

Weddell reports only 30 seamen and 40 soldiers out of a crew of 200 fit for duty, and how Jewett slept with pistols over his head following an attempted mutiny.

On 6 November 1820, Col Jewett raised the flag of the United Provinces of the River Plate and claimed possession of the islands.

Weddell reports the letter he received from Jewett as:[5] Sir, I have the honour to inform you of the circumstance of my arrival at this port, commissioned by the supreme government of the United Provinces of South America to take possession of these islands in the name of the country to which they naturally appertain.

As your views do not enter into contravention or competition with these orders, and as I think mutual advantage may result from a personal interview, I invite you to pay me a visit on board my ship, where I shall be happy to accommodate you during your pleasure.

"[5] Weddell also linked the ceremony to Jewett's claim to the wreck of the Uranie and that it was calculated to make an impression on the masters of ships in the area.

[5] On leaving the Islands, Jewett took the American schooner Rampart as a prize, an incident that had diplomatic repercussions with the United States of America.