Founded in 2008 in Binhai New District, Tianjin Seaharbor Marine Service Co., Ltd. is an independent commercial diving, underwater engineering and ship-repair services company supporting merchant shipping at Tianjin Xingang and the wider Bohai Bay area. The Seaharbor dive team operates surface-supplied air systems together with underwater video and CCTV cameras and offers twenty-four-hour mobilisation to vessels at anchorages and berths, supported by mobile compressors and dive control units. Routine underwater services for shipowners and managers include hull and propeller marine growth cleaning, propeller polishing, blanking of sea chests and overboard discharges, installation of cofferdams and replacement of transducers and speed logs. For statutory and class support, divers perform non-docking in-water hull inspections in lieu of drydocking, hull ultrasonic thickness gauging on plating and bottom structure for intermediate and special periodical surveys, ultrasonic hatch cover tightness testing under IACS UR Z17, watertight integrity verification, and underwater non-destructive testing of welds and structural details using ACFM and magnetic particle methods. NDT and remote inspection programmes are offered alongside the diving work for condition monitoring of ageing tonnage, with reports formatted to the requirements of attending class surveyors. The Tianjin Seaharbor team also takes on emergency hull damage assessments and surveys after grounding or contact incidents, supporting owners and underwriters with timely evidence. The company is recognised as a service supplier by ABS, Bureau Veritas, DNV and the China Classification Society, allowing the in-water survey reports it produces to be accepted by attending class surveyors and Chinese flag-state authorities for merchant tonnage operating in northern China.