Smarter Seas: US Cables Edge Toward Active Defense

Research points to new methods for detecting undersea threats and improving cable security

6 Dec 2025

The US subsea cable industry is testing new technologies that could transform the way the world’s digital infrastructure is monitored and protected. Recent research has shown that optical fibers laid on the ocean floor can act as sensitive detectors, identifying nearby ships and other activity with high precision.

Undersea cables carry more than 95 per cent of global internet traffic and have faced increasing risks, from accidental anchor strikes to deliberate damage. A recent US trial demonstrated that pulses of light moving through fiber strands can detect nearby vessels with over 90 per cent accuracy and locate them within roughly 141 metres. Analysts say the method could help identify ships that have turned off their location transmitters, an issue of growing concern in global shipping lanes.

While commercial deployment remains distant, the findings are prompting operators to assess whether smart sensing could be incorporated into future network upgrades. Companies such as Ciena and SubCom, which play key roles in the subsea ecosystem, may benefit if demand for intelligent monitoring capabilities expands.

Industry observers note that the technology could improve resilience as data traffic surges and geopolitical tensions heighten risks to international connectivity. However, challenges remain, including the need to process vast amounts of sensing data and to adapt older cables for real-time analysis.

Researchers and industry groups see the progress as an early but meaningful step toward more responsive infrastructure. If development continues, subsea cables may soon not only connect continents but also help safeguard them.