Dayang Yihao (Ocean No 1) departs from the city of Sanya, South China's Hainan province on Dec 2, 2013. [Photo/Xinhua]

SANYA -- Research vessel Dayang Yihao (Ocean No 1) departed from the city of Sanya in the southernmost, island province of Hainan on Monday, on China's 30th oceanic exploration mission.

The global voyage, which will last 180 days and cover 19,000 nautical miles, will take the vessel across the Indian Ocean. A total of 339 people are on board, including 254 scientists and engineers.

Among the experiements, scientists will be testing a remotely-operated underwater vehicle, on a series of oceanic surveys mainly on polymetallic sulphide and bioresources.

The Dayang Yihao will anchor in Port Louis of Mauritius three times before its scheduled return to Qingdao in the eastern province of Shandong on May 30, 2014.