SHANGHAI, Sept. 23 (Xinhua) -- The Chinese deep-sea research ship Zhang Jian returned to her home port in Shanghai after finishing a 74-day scientific research trip to the Southern Pacific.

The vessel is the mothership for the Rainbow Fish, a manned submersible capable of diving to 11,000 meters.

During its 9,000 nautical-mile maiden voyage, the research vessel travelled across the South China Seaand the Pacific Ocean to reach the New Britain Trench, which is more than 8,000 meters-deep in the Solomon Sea near Papua New Guinea.

Chinese scientists onboard the vessel carried out joint ocean environmental research with their counterparts in Papua New Guinea. Captain Zha Dawu said the vessel went through several typhoons, including Meranti and Malaka, and an earthquake, during the journey, which tested the ship's navigation performance and research facilities.

China began developing the Rainbow Fish in 2014. It can go much deeper than the previous submersible Jiaolong, which set a Chinese record for a manned submersible when it reached 7,062 meters in the Mariana Trench in June 2012.

Wu Xin, chairman of Shanghai Rainbow Fish Ocean Technology, said that Chinese researchers are preparing to send the explorer ship Zhang Jian to the Mariana Trench later this year, for an unmanned dive of over 10,000 meters.