Photo taken on March 30, 2018 shows researchers examining the unmanned submersible "Hailong 11000" on the Chinese research vessel Dayang Yihao (Ocean No. 1) in the western Pacific Ocean. The unmanned submersible "Hailong 11000" completed its first sea test in the western Pacific Ocean Friday. The submersible entered the 410-meter-deep sea area from the Chinese research vessel Dayang Yihao (Ocean No. 1) at 4:45 p.m. (Xinhua/Chen Hao)