One of the three highlighted discoveries from the shipwreck of Zhiyuan in 2016: first mate of the ship; and the label of the Gatling gun. [Photo provided to China Daily]

Deng commanded the ship to ram the nearby Japanese cruiser Yoshino while his ship was under siege, and is thus honored as a national hero.

"The status of Zhiyuan is incomparable," says Song Xinchao, deputy director of the State Administration of Cultural Heritage.

"And the First Sino-Japanese War, which is symbolized by the ship, changed the relationship between the two countries and the political environment in East Asia for the long term."

Song says the excavation not only promotes patriotism but also sets criteria for similar archaeological projects to follow.

"There are many sunken armor-plated ships from recent history along China's shores," he says, adding that experts lacked the experience and expertise for such excavations until now.

China's first scientific-research vessel specifically designed for underwater archaeology made its maiden voyage in 2014, and its first mission was the excavation of the wreck near Dandong. Advanced technologies like sonar and 3-D modeling were used for detection.