In the autumn of 1969, Batch 0, the preproduction batch built for initial tests had been successfully tested in lakes. Development immediately continued to directly modify Batch 0 torpedoes for oceanic trials, with modification completed in 1971, and oceanic tests begun in 1972, with the design finalized in 1975. However, oceanic environment had caused unexpected problems and from 1974 to the beginning of 1976, over 40 enterprises were ordered by the Yunnan National Defense Office to help Dawn Machinery Factory (Shuguan Jixie Chang, 曙光机械厂) of the Yunnan 6th Machinery Bureau to complete the development of Yu-3 torpedo, but when all of the problems have been solved, it was already years after the designed had already been finalized, and due to the political turmoil in China and the technology bottlenecks, China still had a long way to go. In December 1977, the production version of Yu-3 torpedo was successfully tested in lakes, and from March to October, 1983, work was concentrated on solving the problems discovered during oceanic tests, during which a total of 43 Yu-3 torpedoes were test fired. Finally, in March 1984, the torpedo met all requirement and went into mass production. In May 1988, Han class nuclear submarine had successfully test-launched Yu-3 torpedo at maximum depth in deep water testing facility in Hainan. The torpedo was also given a name as Chinese sturgeon (Zhonghua Xun, 中华鲟).