A ship with 145 scientists aboard set sail for the Pacific in Guangzhou on Thursday (May 22), starting a 250-day expedition.

The expedition, 20th of its kind, has the largest yet complement of scientists, drawn from 24 domestic scientific and educational institutions, according to Wang Fei, deputy chief of the State Oceanic Administration (SOA).

Tao Chunhui, chief scientist for the expedition, said the mission would focus on subjects ranging from deep-sea environment, sulphide in seabed hydrothermal activity in the Pacific, bio-genes and biodiversity in the Indian Ocean.

Tao, who is also a fellow researcher with SOA's No.2 Institute of Marine Studies, was upbeat about the prospects.

"We are better equipped and will achieve more: much of the equipment we have brought along this time is high-tech and new devices developed by the country itself, including an unmanned, remotely operated underwater vehicle (ROV) that could observe the sea and collect samples as deep as 3,500 meters," he said.

China has accomplished a number of feats since 1995 when the country began its first ocean-going scientific expedition, including circumnavigating the globe between April 2005 and January 2006, and finding a new seabed hydrothermal activity area from the depth of 2,800 meters in Mid-Indian Ocean Ridge on its 19th expedition.

During the round-the-globe voyage more than two years ago, Chinese scientists brought back more than 1,000 kilograms of hydrothermal sulphide samples containing copper, zinc and precious metals such as gold and silver.

The vessel, "Dayang Yihao (Ocean No.1)", is scheduled to return to Qingdao, a port city in east China, late next January.

Editor: Yan