WHEN SUBSEA CABLES FAIL, REPAIR COORDINATION BECOMES THE REAL FAULT LINE By Gaya Byrne
In late December 2025, a pressure. cluster of earthquakes off WHY THE CURRENT REPAIR Taiwan triggered one of MODEL STRUGGLES DURING the largest simultaneous MAJOR OUTAGES subsea cable outages the The current repair model was not Asia-Pacific has experi- designed for this type of disruption. Subsea maintenance is orenced in recent memory. ganised around regional mainteAt least six major cable systems owned by different operators failed across routes connecting Japan, Hong Kong, the Philippines, South Korea and Singapore. Repair vessels were in the region and, in some cases, close to the faults. Yet proximity did not translate into speed because the framework governing repair deployment still relies on fixed maintenance zones, cabotage restrictions and multi-jurisdictional permitting. The outage exposed a structural weakness: even where repair capacity exists, the industry still struggles to mobilise it quickly during major multi-fault incidents. The issue is no longer only cable protection or route diversity, but how fast operators, regulators and maintenance providers can coordinate across borders under 96
nance zones, where cable owners pool resources to fund dedicated vessels. In Asia-Pacific, these arrangements include SEAIOCMA and the Yokohama Zone. Under normal conditions, the model works well. It distributes costs and ensures repair capability remains available. What it was not designed for is a simultaneous multi-fault event spanning adjacent zones. When several faults occur at once, vessels in one zone cannot easily move into a neighbouring zone, even when capacity sits idle nearby. There is no standing mechanism for cross-zone sharing during a regional crisis. Two additional constraints compound the problem. Some countries apply cabotage rules requiring repair ships to be locally flagged, preventing foreign vessels from entering national wa-
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ters regardless of proximity or availability. Operators may also require military or territorial permits before repairs can begin. In some regions, those approvals can take three to six months. During the Taiwan outage, some operators sought additional vessels outside standard arrangements to accelerate repairs. But that was an improvised response to a specific emergency, not a system designed to operate at scale.
CLOSING THE GAP BETWEEN POLICY AND PRACTICE In February 2026, representatives from more than 70 countries meeting in Porto backed the Porto Declaration on Submarine Cable Resilience, which called for simpler permitting and lower legal and regulatory barriers, including cabotage. More recent initiatives, including the GUIDE framework launched alongside the 2026 Shangri-La Dialogue, show that critical underwater infrastructure is moving higher on the policy agenda. But recognition is not operational change. Without fast-track permits, clear triggers for cross-zone support, and workable vessel-sharing