Photo taken on March 10, 2019 shows the manned submersible Shenhai Yongshi (Deep Sea Warrior) at a port of Sanya, south China's Hainan Province. China's science ship Tansuo-1 loaded with the manned submersible Shenhai Yongshi (Deep Sea Warrior) returned to its home harbor in Sanya, south China's Hainan Province, on Sunday, after finishing its first expedition in the Indian Ocean. (Xinhua/Guo Cheng)