Speaking in Beijing Saturday, Yan Kai, a senior engineer of China's manned deep-sea submersible research vessel Jiaolong, confirmed that the craft will reach a depth of 7,000 meters below sea level this summer, thereby meeting its design goals.

Yan Kai, a senior engineer of China's manned deep-sea submersible research vessel Jiaolong. [Chen Boyuan / China.org.cn]

Jiaolong, which in Chinese mythology refers to a polysemous aquatic dragon, has successfully completed all of its previous trial runs, carrying three crewmembers to a depth of more than 4,000 meters below sea level on July 22, 2011, and subsequently to a depth of 5,038 meters on July 26. The successful trials marked significant progress in the design of manned deep-sea submersible craft in China.

Mr. Yan, deputy director and chief engineer of the China Ship Scientific Research Center, a state laboratory affiliated to the China Shipbuilding Industry Corporation (CSIC), and Jiangsu Province's delegate to the 11th National People's Congress (NPC), noted that Jiaolong's missions included chemical, mineral and aquatic biological research.

Yan commented that Jiaolong would mainly be used for maritime exploration, especially in relation to deep-sea resources. "The range between 6,000 and 7,000 meters below sea level is rich in resources," he said. "Therefore, we need to have our submersibles explore and conduct research in this range." He added that the deepest point in the South China Sea is only 3,000 meters below sea level.

"That's why we have designed Jiaolong to dive 7,000 meters [below sea level]," he said.

The success of Jialong means that China is the fifth country, following the U.S., Russia, France and Japan, to put such technology to practical use.

Yan noted that the UN International Seabed Authority (ISA) has allocated China an exclusive 5,000 square kilometer area in the Pacific Ocean in which to undertake exploration and research. However, he reiterated that Jiaolong, along with other aquatic vehicles developed in his research center, such as ground-effect vehicles (GEV), were "entirely for civil use."

GEV's ability to cruise at low altitude (between one and six meters above sea level) and thereby maintain stealth by evading radar surveillance, along with its relatively high-speed capability, means that it has long been a subject of interest to both the U.S. and the former Soviet Union.

But Yan argued that his lab's GEV prototype would mainly be served in transportation, particularly in sea rescue missions.