The Jiaolong, a Chinese manned submersible has reached a depth of 5,057 meters at 6:12 a.m.(Beijing time), Xinhua reports.
The test dive, which commenced at 3:38 a.m. on Tuesday in international waters of the Pacific Ocean, achieved complete success, the State Oceanic Administration (SOA) said.
Such a depth means the Jiaolong is capable of reaching over 70 percent of the seabeds in the world, said Wang Fei, deputy director of SOA and director of the leading team of the diving test program.
"It will pave way for a record-breaking 7,000-meter test dive in 2012," Wang added.
Japan is the current world record holder, whose Shinkai 6500 succeeded in diving to 6,527 meters in August 1989.
"The purpose of this diving test program is to find problems with the Jiaolong and improve it constantly," Wang said.
Deep diving poses a challenge to the submersible's capacity to withstand water pressure and its tightness, according to Wang.
"At a depth of 5,000 meters, the Jiaolong withstood great pressure amounting to 5,000 tonnes per square meter," Wang said.
The Jiaolong is the world's first manned submersible designed to reach the depth of 7,000 meters below sea level, according to Xu Qinan, chief designer of the submersible.
Xu said the Jiaolong's equipment was state of art and its digital underwater communication systems and undersea mobility systems allowed the craft to "move back and forth easily under the sea."
The domestically-manufactured Jiaolong, named after a mythical sea dragon, dived to a depth of 4,027 meters with three people aboard in about five hours last Thursday. But its attempt to reach 5,000 meters in another dive on Friday was postponed due to unfavorable sea conditions.
The craft completed 17 dives in the South China Sea from May 31 to July 18 last year, with the deepest reaching 3,759 meters with three crew members on board.
China, which initiated the Jiaolong project in 2002, is the fifth country to send a man 3,500 meters below sea level, following the United States, France, Russia and Japan.