Affiliated with the State Key Laboratory of Ocean Engineering at Shanghai Jiao Tong University, Shanghai Jiao Tong University Underwater Engineering Institute Co., Ltd. is the commercial arm that brings underwater inspection and testing capability developed at one of China's leading naval architecture and ocean engineering research centres to industrial clients. The parent institute operates a 12 by 8 by 10 metre underwater engineering test tank used for submersible position control and propeller experiments, together with deep-sea high-pressure environment simulators that support full-ocean-depth testing of equipment and instruments. Drawing on this background, the SJTU underwater institute company provides commercial diving and remote-vehicle services for in-water hull surveys in lieu of drydocking, hull ultrasonic thickness measurement of plating and internal structures, hatch cover ultrasonic tightness testing under IACS UR Z17, and watertight integrity examination of doors, hatches and penetrations on bulk carriers, container ships and other tonnage. The team also undertakes underwater video and photographic survey of propellers, rudders, sea chests and stern frames, with reports formatted for owner, manager and class use. Engineering support extends to underwater trenching, ROV inspection of submerged structures, monitoring of offshore wind farm foundations and trial measurements during sea trials of newbuilds delivered from Yangtze River Delta yards. The company is recognised as a service supplier by the China Classification Society, so survey reports can be used for statutory and class verifications on Chinese-flagged tonnage and on foreign vessels calling at Shanghai, Ningbo and neighbouring ports along the eastern Chinese coastline serving the Yangtze hinterland.