Tsao Kiang (Chinese: 操江; pinyin: Cāojiāng) was a 640-ton wooden[1] (according to other sources: 600-ton composite-hulled[2]) gunboat, launched in 1869[note 1] by Jiangnan Shipyard, Shanghai, for the Nanyang Fleet.

Acquired in 1872 for Zhili Province by Li Hongzhang the ship served with Beiyang Fleet as a governor's yacht.

[3] Commissioned into the Japanese Navy as a prize of war on 21 September 1894, it was used as a patrol boat along the coastline of Korea during the remainder of that conflict.

On 21 March 1898, Sōkō was de-rated to a second-class gunboat, and was used for surveys of the Kurile Islands in Japan's northern waters.

In 1924, it was sold off by the Japanese government to a private buyer in Nishinomiya, Hyogo and continued to be used as a civilian transport under the name Sōkō Maru until 1964.