ON BOARD SHIP XIANGYANGHONG 09, May 31 (Xinhua) -- China's manned submersible "Jiaolong" will be despatched on its fifth, and last, dive of the year in the Mariana Trench Thursday.

"According to the latest forecast, the weather and sea conditions will permit the scheduled dive," said Wen Lianjie, the forecaster onboard.

Jiaolong will descend to a depth of 6,700 meters.

Its first dive of the year in the world's deepest-known trench took place on May 23, and it reached a depth of 4,811 meters.

The second and third dives, on May 25 and 27, reached depths of 6,300 meters and 6,544 meters.

During the fourth dive, on Tuesday, the submersible reached a depth of 6,699 meters, and recorded images of two swimming snailfish.

The mission is the third and final stage of China's 38th oceanic scientific expedition, which features surveys in the Yap and Mariana trenches.

The expedition is scheduled to finish on June 18.