How underwater blind spots in the South China Sea could help China outsmart US

The team, led by associate professor Ma Benjun, wrote that locating mines in these blind spots could make them harder to detect.

By: Express Web Desk

New Delhi | Updated: August 31, 2025 08:14 PM IST

3 min read

Tests cited in the research suggest that mines placed in these shadow zones stand a much greater chance of avoiding detection. (Photo: X/@AndreaAlbion)

Chinese military researchers are exploring ways to turn the underwater terrain around the Paracel Islands into a minefield that could threaten enemy submarines, according to a report in the South China Morning Post (SCMP).

The proposal builds on lessons from the USS Connecticut incident in 2021, when one of the US Navy’s most advanced nuclear submarines struck an uncharted seamount in the South China Sea.

Researchers from the People’s Liberation Army’s Dalian Naval Academy and Harbin Engineering University said in a study published in Technical Acoustics that the rugged underwater landscape around the Paracels contains “acoustic shadow zones”. These are areas where sonar signals fail because of the way sound bends, reflects or disappears around seamounts.

The team, led by associate professor Ma Benjun, wrote that locating mines in these blind spots could make them harder to detect. “Research on site selection can help identify optimal positions on the sea floor, increase concealment and ensure deployed assets are difficult to find,” they noted, according to SCMP.

The study described the mines as large devices that can remain dormant on the seabed for long periods, coated to blend with the terrain. They would be equipped with sensors able to recognise vessels by their sound profiles and activate only against pre-approved targets such as submarines or carrier groups.

Tests cited in the research suggest that mines placed in these shadow zones stand a much greater chance of avoiding detection in some cases up to 80 per cent, SCMP reported.

The Paracel Islands, called Xisha by China and Hoang Sa by Vietnam, are occupied by Beijing but also claimed by Taipei and Hanoi. The area, about 300 nautical miles south of China’s Hainan Island, has seen extensive Chinese military construction, including an airfield and radar stations.

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The United States does not take a position on sovereignty but continues to carry out naval patrols close to Chinese-held reefs.

Chinese researchers said that if developed, the system could challenge America’s long-standing edge in undersea warfare, where its Seawolf and Virginia-class submarines are designed to operate with extremely low noise levels.

Minefield proposal is part of wider Chinese efforts in anti-submarine warfare, which also involve seabed sonar arrays, underwater drones and surveillance aircraft.

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