China’s upgraded manned deep-sea submersible Jiaolong is recovered on October 2, 2026, after completing its 465th dive, during which it reached a depth of 7,056.9 meters. Photo: Xinhua

China’s upgraded manned deep-sea submersible Jiaolong has successfully completed multiple 7,000-meter-class sea trials in the Philippine Basin, confirming the reliability and safety of the upgraded submersible and its domestically produced key components and strengthening China’s technological edge in manned deep-sea exploration equipment, the Xinhua News Agency reported on Tuesday. 

The sea trials were conducted as part of the second leg of China’s 100th oceanographic expedition. The submersible completed three test dives in the Philippine Basin, including two dives to depths exceeding 7,000 meters, reaching a maximum depth of 7,056.9 meters. All test parameters met the requirements for 7,000-meter-class sea trials. 

Sun Yongfu, a researcher at the National Deep Sea Center, said the sea trials fully verified the reliability and safety of Jiaolong following its iterative upgrades and the replacement of key components with domestically produced alternatives, consolidating and enhancing China’s technological advantages in manned deep-sea submersible technology. 

Before the scientific expedition, the submersible received major upgrades, including a 7,000-meter-class high-energy-density lithium battery pack, domestically developed low-noise DC thrusters and advanced hydraulic and imaging systems. The upgrades introduced technological innovations across key components and systems, including power supply, propulsion, hydraulics, electrical systems, and communication and observation, significantly enhancing the submersible’s operational capabilities. 

According to Sun, following its upgrades and the localization of key components, submersible conducted multiple scientific missions in different sea areas to investigate deep-sea resources and marine ecosystems. 

These scientific expeditions will further deepen international cooperation in marine science, significantly advancing China’s deep-sea exploration and research, and contribute to the country’s goal of becoming a maritime power, Sun said. 

Global Times