Jiaolong challenges world's first 7,000-meter dive

China's manned submersible, Jiaolong, made its fourth dive in the Mariana Trench on Sunday morning to attempt the world's first 7,000-meter dive below the surface of the Pacific Ocean.

The dive started at 7 am Sunday local time (2100 GMT Saturday) in heavy rain and with the Rafale at 6 levels.

Three oceanauts, Ye Cong, Liu Kaizhou and Yang Bo, are conducting the dive with the support of nearly 100 scientists on board.

The oceanauts had succeeded in reaching depths of 6,671, 6,965 and 6,963 meters in their previous three dives from June 15 to 22, well surpassing the record of 5,188 meters last July.