The Matsu Islands are an archipelago of 36 islands in the East China Sea, alongside the southeastern coast of mainland China. Administered by Taiwan since 1949, they form part of a wider group of outlying islands that includes Kinmen and Penghu, all lying in the Taiwan Strait. The Matsu Islands are connected to Taiwan's main island by two submarine cables, Taima No.2 and Taima No.3, with Taima No.4 soon to follow.
The Taiwan Strait is shallow, with an average depth of 70m, leaving its seafloor cables exposed to damage from ship-based activity such as snagging by fishing equipment or anchors. These particular cables have been remarkably unlucky. Between 2018 and 2022, the links between Taiwan and the Matsu Islands were cut 27 times, and there were four major outages in the three years from 2023 to 2025.
The problem is not confined to Taiwan. The Baltic Sea holds a dozen or so submarine communications cables, along with undersea electricity and gas pipelines, and has seen 11 disruptions to these systems since 2023. Globally, an estimated 1.5M kilometres of subsea communications cables serve 607 in-service systems. Satellites could not replace them if they failed, which could leave some communities totally isolated with severe logistical and economic consequences.
The cables also face deliberate threats. During the First World War, British cable ships cut five German transatlantic and European telegraph cables in 1914, forcing Germany to rely on radio that British intelligence could readily eavesdrop on. Geological events such as submarine earthquakes and landslips, along with anchors, fishing gear and deliberate attacks, remain ongoing risks. Operators respond by armouring cable segments near shore with steel jacketing, while deep-sea segments use a lighter design.
Source: Hacker News · Summarized by HeadlinesBriefing