ABOARD DEEP SEA NO. 1, Aug. 18 (Xinhua) -- Jiaolong, China's manned deep-sea submersible, on Sunday completed its 300th dive since its maiden mission in August 2009.

Jiaolong, with a crew of one scientist and two submariners, conducted the dive in the Western Pacific Ocean. It was the first of 18 planned dives in an ongoing scientific expedition.

The submersible is being carried by China's Deep Sea No. 1 research vessel, which has Chinese and foreign scientists aboard and embarked from Qingdao in east China's Shandong Province on Aug. 10.

During its 45-day expedition to the Western Pacific Ocean, Jiaolong is scheduled to collect deep-sea organisms, seawater and sediment, aiming to deepen our understanding of the unique ecosystems and environments of seamounts.

Since 2009, Jiaolong has explored waters in the Pacific Ocean, Indian Ocean and Atlantic Ocean, enabling a total of 900 trips down into the deep sea.