Two undersea cables off Perth reportedly damaged in close succession amid suspicious vessel activity

Two undersea cables operated by Subco, Indigo-West and Indigo-Central, reported shunt faults in rapid succession, with the damage occurring in close proximity. The faults were detected within a federally designated Cable Protection Zone off the coast of Perth, an area intended to safeguard critical infrastructure. The timing of the faults coincided with the presence of a vessel in the vicinity, raising suspicions of deliberate interference. While shunt faults can occur naturally due to environmental factors, the clustering of two incidents in a protected zone suggests a non-random cause. The Australian Federal Police have initiated an investigation, indicating the severity of the event and the potential for criminal intent.

The incident underscores the fragility of undersea cables, which form the backbone of global data transmission. Shunt faults, caused by insulation failure, can lead to short circuits and require physical repairs, often involving specialized ships and extended downtime. For engineers, this means assessing the resilience of network architectures, particularly in regions reliant on a limited number of cable routes. Redundancy plans must now factor in the possibility of coordinated physical attacks, not just natural wear or accidental damage. The cost of such disruptions extends beyond repair expenses, including lost revenue, degraded service quality, and reputational damage for providers.

Geopolitical tensions have increasingly targeted undersea infrastructure, with nation-state actors suspected in similar incidents elsewhere. The proximity of the vessel to the fault location and the protected status of the zone amplify concerns about sabotage. If confirmed, this would not be an isolated case; other countries have reported disruptions linked to suspicious maritime activity. For engineers, this shifts the risk landscape from technical failures to hybrid threats, requiring collaboration with security agencies and maritime authorities. Monitoring vessel traffic near cable routes may become a standard practice, alongside traditional network monitoring tools.

The response to this incident will set a precedent for how Australia and other nations protect undersea cables. Current protection zones, while legally enforced, may need additional surveillance or enforcement mechanisms to deter interference. Engineers may need to design systems with built-in resilience, such as self-healing networks or alternative routing protocols, to mitigate the impact of physical damage. The investigation’s findings will also influence policy discussions about international norms for safeguarding critical infrastructure. Until then, operators must treat such incidents as potential security breaches, not just technical failures.