LEGAL & REGULATORY MATTERS NAUTICAL CHARTS AND SUBMARINE CABLES by Andrés Fígoli Submarine telecommunications cables form the invisible backbone of the global digital economy, yet they rest in one of the most complex and heavily used environments on Earth: the seabed, often described as the “last frontier” of the planet.
phisticated and widely used. Industry publications such as SubTel Forum, offer interactive maps that illustrate the routes, landing points, and ownership structures of cable systems around the world. These tools have significantly improved transparency in a sector that was once comparatively opaque, especially when dealing with telecom national regulators that may be unaware of the presence of these vital infrastructures in their waters.
Their protection depends not only on engineering resilience and regulatory permits, but also on something far more traditional — accurate nautical charting. Nautical charts serve as the official reference for mariners, identifying submarine cables as features that require caution and, in certain cases, avoidance. Without proper charting, cables remain exposed to preventable risks from anchoring, fishing, dredging, and other maritime activities.
Such platforms are undeniably valuable. They support:
Unlike commercial cable maps or industry visualization platforms, official nautical charts are produced and maintained by national hydrographic offices in accordance with international standards developed by the International Hydrographic Organization (IHO). These charts carry legal authority and are used for navigational decision-making by vessels engaged in international voyages. What appears on a nautical chart has legal consequences: it shapes expectations of prudent seamanship, influences liability determinations, and establishes whether adequate notice of submarine infrastructure has been provided to third parties.
They allow stakeholders to visualize global connectivity patterns and identify regional or national infrastructure concentration points, redundancy gaps and regional dependencies. For analytical and strategic purposes, they are indispensable.
This article explores why nautical charts are central to the legal and operational protection of submarine cables. It examines how cable positions are communicated to hydrographic authorities, how updates following installations and repairs are incorporated into official charts, and what risks arise when data flows are incomplete or delayed.
This distinction is not merely technical — it is legal and operational. A nautical chart issued by a national hydrographic office is an official state document. It is a legally recognized navigational instrument and, in many jurisdictions, its use on board is mandatory when navigating within territorial waters. Nautical charts — whether in paper format or as Electronic Navigational Charts (ENCs) displayed through 30-years-old Electronic Chart Display and Information Systems (ECDIS systems) — define the maritime safety baseline. They are relied upon by masters, insurers, port authorities, courts, and mar-
1. NAUTICAL CHARTS VS. GLOBAL CABLE MAPPING PLATFORMS Over the past decade, global submarine cable mapping platforms have become increasingly so112
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• Market transparency and competitive analysis • Public policy discussions and strategic planning • Investment and financing decisions • Infrastructure coordination • Academic and geopolitical research
However, their function must not be confused with that of official nautical charts. Global cable maps are not nautical charting systems. They are not designed for navigation, nor do they constitute authoritative hydrographic products, and of course they are not recognized as official sources for safe passage planning.