China's most sophisticated research vessel -- named Kexue, or Science -- left for the west Pacific on Tuesday afternoon from the eastern port city of Qingdao, beginning its first ocean expedition.

Its research will focus on the Pacific currents, regional climate and deep-sea ecology.

A total of 46 scientists and technical staff are on board. They are expected to arrive at the targeted area on Thursday and will carry out marine geophysical surveys and biological sampling, said Li Chaolun, chief scientist of the expedition.

The ship is expected to return in the second half of May.

Weighing 4,711 tonnes, Kexue is 99.8 meters long and 17.8 meters wide. With a cruising capacity of 15,000 nautical miles and a top speed of 15 knots, it can travel with a crew of 80 for 60 days.