Staff members tether the research vessel Kexue at its home port in the Qingdao West Coast New Area in Qingdao, east China's Shandong Province, Nov. 5, 2018. The research vessel returned to Qingdao on Monday from a 31-day scientific expedition to the West Pacific. (Photos: Xinhua)

The research vessel Kexue is seen anchored at its home port in the Qingdao West Coast New Area in Qingdao, east China's Shandong Province, Nov. 5, 2018.

Family members of the staff onboard the research vessel Kexue wait for their disembarkation at a port in the Qingdao West Coast New Area in Qingdao, east China's Shandong Province, Nov. 5, 2018.

The research vessel Kexue is seen anchored at its home port in the Qingdao West Coast New Area in Qingdao, east China's Shandong Province, Nov. 5, 2018.

Staff disembark from the research vessel Kexue at a port in the Qingdao West Coast New Area in Qingdao, east China's Shandong Province, Nov. 5, 2018.