China's manned submersible Jiaolong begins its first South China Sea dive this year on April 26, 2017. [Photo/Xinhua]

The submersible is expected to conduct its first South China Sea dive this year on Wednesday if the weather conditions allow, according to Wu Changbin, general commander of the second stage of the expedition.

During the mission, which lasts until May 13, scientists hope to choose a site for experimenting the collection of polymetallic nodules and complete geological and biological surveys.