Grijalva River
"Petrita" was a small, swift, screw steamer built in the United States and in Mexican service when the Mexican War broke out in 1846. She was one of two steamers and various other vessels in the Grijalva River at the town of Frontera when a U.S. Navy squadron commanded by Commodore Matthew C. Perry surprised Mexican forces there and captured her along with the other Mexican vessels. She was added to the American squadron.