Chinese technicians have, for the first time, controlled a remotely operated underwater vehicle (ROV) to reach about 3,000 meters beneath the sea's surface in the South China Sea and successfully carried out a series of tests recently.

During the five-day mission, technicians from Yantai Salvage carried out tests on the ROV's sensors, auxiliary equipment, mechanical hydraulic system, data transmission and automatic control system.

The ROV dove 1,180 meters deep on April 6, 2,951 meters on April 7 and 2,735 meters on April 8.

During the April 8 dive, technicians released the ROV from the umbilical cable and directed it 600 meters underwater, putting a sign of "Yantai Salvage of the Ministry of Transport" into the seabed.

The success of tests showed that China has gained the ability to carry out rescue work and marine engineering missions within 3,000 meters beneath the sea's surface.