Suspicious Tanker Movements Spark Cable Break Probe in Australia

A Suspicious Pattern Off Perth

Australian authorities are facing pressure to investigate a subsea cable incident after a UAE-managed product tanker was tracked moving in a repeated, racetrack-like pattern directly over a charted submarine cable zone off Perth. According to a report by The Maritime Executive, the unusual navigation coincided closely with an outage affecting two fiber optic cables in the same protected area, prompting the cable operator to raise the possibility of a deliberate security incident rather than an accident.

The breaks occurred back-to-back within a government-designated cable protection zone, at the same time the vessel was observed crossing the area multiple times. Security consultancy Windward reportedly confirmed the ship’s presence and identity independently, lending weight to the timeline.

Operator Calls for Federal Investigation

Bevan Slattery, founder and CEO of cable operator Subco, acknowledged the vessel’s movements could be coincidental but said the pattern was concerning enough to warrant urgent scrutiny from the Australian Federal Police. He noted that if confirmed as deliberate, it would mark a second incident of its kind within a federally declared cable protection zone, underscoring how dependent the country is on a small number of physical links to the outside world — just 16 cables connect Australia to the rest of the world’s networks.

Because the affected cables lack automatic diagnostic systems, Subco says it cannot determine the root cause — including whether an anchor drag was responsible — until a physical inspection is carried out. That uncertainty matters: according to the International Cable Protection Committee, anchor dragging accounts for roughly one-third of all cable breaks worldwide, making it the most plausible innocent explanation even amid suspicion. Notably, sea conditions at the time were reported as calm, which narrows the range of accidental explanations somewhat, though it does not rule them out entirely.

A Pattern Seen Elsewhere

Researchers monitoring subsea infrastructure risk point out that this is not an isolated concern. ASPI researcher David Brewster told the ABC that Europe and the waters around Taiwan have seen a string of cable-cutting incidents over the past several years, with many cases pointing toward state actors — namely Russia and China — using deniable methods to test disruption capabilities.

A newly released review from the National Security College at the Australian National University reinforces this concern, warning that state actors appear to be actively probing and testing cable infrastructure during peacetime as part of broader hybrid warfare preparation, with the goal of being able to degrade connectivity quickly if a conflict began.

What This Means for Ship Operators and Managers

For tanker owners, managers, and charterers, this incident is a reminder that vessel track data is now scrutinized far beyond port state control and commercial performance metrics. AIS and satellite tracking records can be — and increasingly are — cross-referenced against subsea infrastructure maps by security researchers, cable operators, and national authorities. A vessel’s behavior near sensitive undersea assets, even if entirely innocent (such as slow-steaming, drifting, or repositioning during a technical stop), can now trigger geopolitical-level attention and reputational risk for the operator and flag state involved.

This case also highlights the practical limits of casualty investigation when subsea assets lack integrated monitoring. Just as with hull, cargo, and bunker surveys, the ability to establish facts after an incident depends heavily on the presence of reliable diagnostic and inspection data. Without automatic cable monitoring, Subco is left waiting for a physical inspection before it can even confirm the mechanism of failure — a situation analogous to disputes at sea where the absence of an independent survey record leaves owners, charterers, and insurers arguing over probability rather than evidence.

As incidents involving vessel behavior near critical undersea infrastructure draw increasing regulatory and media attention, operators should expect greater emphasis on transparent voyage documentation and readiness to cooperate with investigations — even when no wrongdoing is suspected. Maintaining clear records of course changes, technical stops, and anchoring activity near known cable zones may become an increasingly important part of standard operational practice.

Reviewed by Ibrahim Halil Ceylan, Marine Surveyor at Apeks Marine.