Submarine Cable Resilience Under Scrutiny
Original: Submarine cable resilience
Why This Matters
Repeated cable cuts expose how thin the margin of resilience is for critical internet infrastructure.
APNIC's Geoff Huston examines submarine cable vulnerability, citing 27 cuts to Taiwan-Matsu cables between 2018–2022, 4 major outages in 2023–2025, and 11 Baltic Sea disruptions since 2023.
The Matsu Islands, administered by Taiwan and lying in the shallow East China Sea (average depth: 70m), depend on just two active submarine cables — Taima No.2 and No.3 — with a third, No.4, in progress. That shallow seafloor makes cables easy targets for fishing gear and ship anchors. Between 2018 and 2022, those cables were cut 27 times. Four major outages followed between 2023 and 2025. The Matsu situation is not isolated. The Baltic Sea, another shallow body with roughly a dozen submarine communications cables plus undersea energy pipelines, has seen 11 system disruptions since 2023. Globally, 607 in-service submarine cable systems span an estimated 1.5 million kilometres of seafloor, carrying the overwhelming majority of the world's international data traffic. Satellite systems, despite recent growth, cannot absorb that volume — a widespread outage would leave some communities entirely cut off. APNIC's Huston frames these repeated incidents as a stress test for infrastructure resilience planning, emphasizing that current fault rates in specific high-risk corridors are far above what redundancy models typically assume.