On the night of July 29, while an Argentine convoy of troops and military equipment carried out a crossing to the Banda Oriental, escorted by the Río de la Plataschooner that was commanded by captain Leonardo Rosales, admiral Brown, with a force integrated by the 25 de Mayofrigate (flagship), the Congreso, Independencia, Republica and General Balcarcebrigs, the Sarandí schooner and other small ships in a total of 18, was in his usual base waiting for the convoy's arrival and left the port in an unsuccessful attempt to surprise the Brazilians.[4]
Admirals James Norton and William Brown
The Brazilian fleet, commanded by captain Norton, was composed of the Nichteroy frigate, the corvettesLiberal, Maria da Glória, Maceió and Itaparica, the brigs Pirajá, Caboclo and 29 de Agosto, the schooners Leal Paulistana, Dona Paula, Conceição and 7 de Março and a few gunboats, with a total of more than 200 guns.[1][2] From 8 o'clock onwards, the fleet continued to sail until midnight, when it anchored to the east of the outer channel, near Ensenada waiting for the return of the convoy to attack it, which it finally did near the coast of Quilmes.
"During the late evening of July 29, Brown, commanding eighteen small warships, once again slipped out of port and unsuccessfully attempted to surprise the Brazilians. The next day, as the Argentine squadron approached the Brazilians at a right angle, Norton split his force, catching the Argentine between two fires. Brown in the 25 de Mayo reversed course. Those ships in the Argentine van came under heavy fire. After three hours of fighting, the Argentine fleet escaped into shallow water. The 25 de Mayo, a floating wreck, was towed into Los Pozos and capsized in a strong southwester. The Brazilian lost six dead and twenty wounded; among this latter group was John Pascoe Grenfell who lost an arm. Argentine losses might have been as high as one hundred dead and one hundred wounded". [4]
Carranza, Angel Justiniano (2018). Campañas Navales de la República Argentina: cuadros históricos (in Spanish). Forgotten Books. ISBN978-1-332-48169-9.
Donato, Hernâni (1987). Dicionário das Batalhas Brasileiras (in Portuguese). São Paulo: Editora Ibrasa.
Garcia, Rodolfo (2012). Obras do Barão do Rio Branco VI: efemérides brasileiras (in Portuguese). Brasilia: Fundação Alexandre de Gusmão. ISBN978-85-7631-357-1.
Scheina, Robert L (2003). Latin America's Wars: The Age of the Caudillo, 1791–1899. Dulles: Potomac Books Inc. ISBN978-1-57488-450-0.
Vale, Brian (2000). A War Betwixt Englishmen: Brazil Against Argentina on the River Plate. 1825–1830. London: I. B. Tauris. ISBN1-86064-456-2.