China's second manned submersible returned on Tuesday morning to Sanya, south China's Hainan Province after a trial operation at a depth of 4,500 meters. The submersible carried out 338 tests in the South China Sea. The submersible is named Shenhai Yongshi, or Deep Sea Warrior. During the underwater journey, it made 28 dives. The manned vessel departed from Sanya City on August 16. With more than 90 percent of the core components developed and made by China, the submersible marks another Chinese breakthrough in deep sea exploration.