WHERE IN THE WORLD ARE THOSE PESKY CABLESHIPS? BY KIERAN CLARK
A GLOBAL ANALYSIS OF CABLE SHIP PATTERNS, INFRASTRUCTURE PROXIMITY, AND PROJECTED ACTIVITY USING AIS DATA
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he global subsea cable network—the invisible backbone of the internet—relies on a small fleet of specialized vessels for cable installation, inspection, and maintenance. These cable ships play a vital role in ensuring connectivity between continents, yet their operational patterns remain difficult to interpret. Most tracking is based on AIS (Automatic Identification System) data, which shows where ships are and how fast they’re moving, but offers little direct information about what the vessels are actually doing. This article presents the latest results from a geospatial analysis of cable ship movement using 7,360 AIS-derived data points collected between 1 May and 30 June 2025. Building on our previous methodology, this analysis identifies where cable ships cluster, how their behavior varies across global regions, and what their proximity to infrastructure might reveal about their roles—whether conducting cable repairs, deploying new systems, or simply waiting on standby. The AIS dataset was compiled at six-hour intervals, generating a consistent view of vessel locations, movement speeds, and identities. Points where ships remained slow or stationary for extended periods were flagged as likely idle events. These idle points were then classified using a proximity-based model: if a ship remained within 50 kilometers of a known cable depot or factory for more than 24 hours, a projected classification was applied:
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• Installation if near a factory • Maintenance if near a depot • Unclassified if no infrastructure was nearby or conditions were inconclusive If both a depot and factory were within range, installation was prioritized—based on historical trends suggesting factory-adjacent sites (e.g., Calais or Kitakyushu) are more commonly used for system deployment rather than repairs. The 50 km threshold accounts for both geolocation uncertainties in infrastructure coordinates and positional drift in AIS data, which may not consistently reflect specific berth positions or anchoring locations. This range offers a reason-