China has a brand new manned submersible that can reach a depth of four-and-half kilometres. It's been eight years in the making, and has passed 28 underwater tests. The Shen-hai Yong-shi or "Deep Sea Warrior" was certified in Beijing on Thursday. Experts say the new submersible is quite advanced, and will boost China's deep sea exploration capability. The Deep Sea Warrior follows the Jiaolong into service - that vessel set a record by diving 7-thousand-62 meters into the Mariana Trench.