on 16 january 1918, chinese southern revolutionary troops attacked the little warship above chenglin; during which "monocacy" prevented the rebels from firing on a japanese steamer standing down stream. one crewman was killed and two others were wounded in the short but fierce fight. in june 1920, she was reclassified as pg-20 and a month later she engaged in another battle. three years later, in february and march 1923, the gunboat operated against bandits holding up american missionaries and firing upon u.s. flag vessels above kiangnang, rescuing the syracuse medical unit and a number of american families. later that year, she protected u.s. river commerce from warlord armies and then in august, she established friendly relations with the governor of kiangsin province.