The Sungari Fleet was active on the Sungari, Amur and Ussuri rivers from 1933, and received additional gunboats from Japan. However, it proved hopelessly inadequate during the Pacification of Manchukuo, and the Japanese instituted numerous training programs in an attempt to raise its capabilities. Reserve or retired Japanese officers were assigned to the Sungari Fleet, and Manchukuo cadets were sent to study navigation and gunnery at the Imperial Japanese Navy Academy.