A Chinese ship has tested a new device capable of slicing through submarine data cables thousands of meters beneath the ocean surface. That demonstration may exacerbate security concerns over a spate of suspected sabotage incidents targeting undersea communications and power cables from the Baltic Sea to the Pacific Ocean. The trial took place at a depth of 11,483 feet (3,500 meters) during a deep-sea science expedition involving the Chinese research ship named Haiyang Dizhi 2, according to the South China Morning Post. That ship is equipped with a 150-ton crane, a 10-kilometer fiber optic winch, and a helicopter landing platform. It has shown the capability to deploy deep-sea remotely operated vehicles in previous missions. The South China Morning Post cited a report in the China Science Daily, an official, Chinese-language news publication run by the Chinese Academy of Sciences. The latter claimed that “the sea trial has bridged the ‘last mile’ from deep-sea equipment development to engineering application.” This is the latest of multiple dual-use technologies for cutting undersea cables developed by Chinese military and civilian organizations over the years. Previous examples include People’s Liberation Army naval organizations filing patents for cable-cutting and retrieval tools, as well as Lishui University filing a patent for a cable-cutting device that could be towed behind a vessel for emergency use, according to the Jamestown Foundation think tank based in Washington, DC. Such technology also debuts at a time when a growing number of Chinese-registered ships have been involved in damaging subsea data cables and even pipelines across the world. How it works beneath the waves The cable-cutting technology is reportedly designed to cut subsea cables at maximum depths of 13,123 feet (4,000 meters). Its design was first published in the Chinese-language journal Mechanical Engineer in 2025 and attributed to researchers at the China Ship Scientific Research Center and the State Key Laboratory of Deep-sea Manned Vehicles. The submarine cable-cutting technology relies on an electro-hydrostatic actuator consisting of a hydraulic pump, an electric motor, and a control unit. That compact device enables a diamond-coated grinding wheel to exert enough force to cut through undersea cables armored with layers of steel, rubber, and polymer, according to the South China Morning Post’s earlier reporting from 2025. It’s also small enough to fit aboard one of China’s many underwater remotely operated vehicles.