(Photos: Xinhua)

China's most advanced self-developed 4,500-meter-level unmanned submersible Qianlong-3 completed its first dive in the South China Sea on Friday.

It successfully reached the projected depth of 3,750 meters at 6 am and started its tests after sinking at a speed of 50 meters per minute.

The orange clownfish-shaped autonomous underwater vehicle is 3.5 meters long, 1.5 meters high and weighs 1.5 tons.

Qianlong-3 is on a 9-hour diving journey and will reach the 3,900-meters in the afternoon, before it returns to sea level at 3 pm, according to Liu Jian, chief designer of the submersible.

“The dive is aimed at testing Qianlong-3’s comprehensive performance, and will help verify its technical indicator and functions.

“The sea test and experimental application this time can further consolidate China’s basic technologies in this field, improve its capability in exploring International waters and further promote the research into the deep sea", said Li Bo, deputy director at China Ocean Mineral Resources R & D Association. 

(Compiled by Shan Xin)