The Chinese research vessel Haiyang-6 is on its way to the region surveying undersea mineral resources.
Xinhua reports the ship set out from Guangzhou for the Pacific Ocean on Tuesday to carry out a five-month study.
It's carrying an expedition team of 96 members.
Last year, the vessel and a research crew of 60 made a four-month voyage to probe deep-sea cobalt reserves in the Pacific Ocean.