 During the Sino-South Vietnamese naval clashes on 19 January 1974, two boats of this class, # 281 & # 282 (two out of the eight total in Chinese inventory) participated in the latter half of the battle, the fastest Chinese units in the conflict.Originally the units were waiting at Yongxing Island, but due to the problem of communications, they were not notified until the battle was already in progress.Over 100 were built, but as newer submarine chasers enter service, this class is steadily being decommissioned.