Unmanned submersible ‘Hailong III’ is put into the sea for a test from the vessel Dayang Yihao (Ocean No 1), March 24, 2018. The submersible completed a 400-meter-deep sea test in west Pacific Ocean on March 24. Chinese research vessel Dayang Yihao left Qingdao, Shandong province, on March 20, taking scientists on a 45-day scientific ocean expedition.[Photo/Xinhua]

Unmanned submersible ‘Hailong III’ is put into the sea for a test from the vessel Dayang Yihao (Ocean No 1), March 24, 2018. The submersible completed a 400-meter-deep sea test in west Pacific Ocean on March 24. Chinese research vessel Dayang Yihao left Qingdao, Shandong province, on March 20, taking scientists on a 45-day scientific ocean expedition.[Photo/Xinhua]