During the 1947 Paraguayan civil war, the crews of "Humaitá" and "Paraguay", at the time undergoing a major overhaul in Buenos Aires took control of the vessels and arrested the officers loyal to president Higinio Morínigo. They sailed up to Carmelo, in Uruguay. The vessels had to be armed with machine guns instead of antiaircraft cannons, because the older ones had been dismounted to be replaced in Argentina. The crew also picked up a cache of 250 rifles. The rebel ships then steamed up the Paraná river, and near Paso de la Patria, Argentina, the government T-6 Texans aircraft unleashed a series of airstrikes on the rebel flotilla, disabling "Humaitá", which was hit by a bomb that destroyed the central gunfire director and became stranded off Ituzaingó. Rebel personnel from "Paraguay" landed on the islands of Corateí and San Pablo, but they were eventually isolated and captured on 25 July by loyal troops carried by the transport ships "Tirador" and "Capitán Cabral". "Humaitá" was afloat again by 13 August, when she and her sister ship tried to enter the Paraguay River. Both ships were shelled by a loyal coastal battery and had to withdraw to Itá Ibaté in Argentina. The gunboats were interned by Argentine authorities, and eventually handed over to the Paraguayan government in August, when the rebellion was finally crushed. In 1955, "Paraguay" became involved in the aftermath of Argentina's Revolucion Libertadora, when former president Juan Domingo Perón went into exile aboard the Paraguayan vessel.