By Alexandra Anargyrou, Analyst KEDISA
Introduction: Rethinking Ocean Law Beyond the Surface
The Law of the Sea has long been conceptualized as a horizontal legal order, structured around maritime zones, navigational freedoms, and jurisdictional lines drawn across the surface of the ocean. From territorial waters to exclusive economic zones (EEZs), legal analysis has traditionally focused on delimitation, navigation, and surface-level activities. Yet this surface-centric approach increasingly obscures a critical transformation in maritime geopolitics: the strategic shift from surface control to subsurface dominance.
Technological advances in seabed mapping, offshore resource extraction, submarine cables, and deep-sea exploration have elevated the seabed from a peripheral legal concern to a central domain of geopolitical competition. This article argues that while UNCLOS projects an image of comprehensive regulation, its effectiveness diminishes with depth. The deeper governance moves below the surface, the more fragmented, ambiguous, and strategically malleable the legal regime becomes.
To capture this transformation, the article introduces two analytical concepts: vertical sovereignty, referring to the stratified nature of legal authority from surface waters to the seabed, and legal depth, denoting the inverse relationship between physical depth and legal clarity. Together, these concepts allow for a re-evaluation of ocean law not merely as a spatial framework, but as a layered legal order whose blind spots increasingly shape international behavior.
The Legal Architecture of the Seabed Under UNCLOS
UNCLOS formally distinguishes between the water column and the seabed, assigning differentiated legal regimes depending on both location and function. Coastal states exercise sovereignty over the seabed and subsoil of the territorial sea, and sovereign rights over the continental shelf for the purpose of exploring and exploiting natural resources (UNCLOS, arts. 2, 77). Beyond national jurisdiction lies “the Area,” designated as the common heritage of mankind and administered by the International Seabed Authority (UNCLOS, art. 136).
At first glance, this structure appears legally robust. Yet the continental shelf regime introduces a critical conceptual rupture: seabed rights exist ipso facto and ab initio, independent of proclamation or effective occupation. This decoupling of seabed rights from surface jurisdiction generates legal certainty in principle, but strategic ambiguity in practice—particularly in regions where maritime boundaries remain unsettled.
UNCLOS provides limited guidance on preparatory activities such as seismic surveys, seabed mapping, or exploratory research in disputed areas. These activities fall short of exploitation, yet often exceed purely scientific inquiry. As a result, the seabed becomes a legal liminal space where states can advance their strategic position without triggering clear legal violations or effective enforcement mechanisms.
Vertical Sovereignty and the Problem of Legal Depth
The concept of vertical sovereignty challenges the implicit assumption that maritime jurisdiction operates uniformly across depth. In reality, sovereignty at sea is layered: strongest at the surface, progressively weaker below it. Naval presence, freedom of navigation, and surface activities are highly visible and politically sensitive, often subject to immediate diplomatic or military response. By contrast, seabed activities are technologically opaque, legally complex, and difficult to monitor.
Legal depth captures this phenomenon analytically. As physical depth increases, legal precision and enforceability decrease. The seabed thus represents a zone where international law is present but thin—sufficient to legitimize claims, yet insufficient to constrain strategic maneuvering. This structural condition reflects the technological and political realities of the era in which UNCLOS was negotiated, when deep-sea capabilities were limited and geopolitical competition remained predominantly surface-oriented.
In today’s strategic environment, however, this mismatch between legal design and technological capacity has become consequential. States increasingly operate within this vertical gap, leveraging legal uncertainty to pursue incremental gains while avoiding escalation.
Seabed Activities as Strategic Practice
Seabed-related operations are uniquely suited to what international relations scholarship describes as grey-zone strategies: actions that remain below the threshold of armed conflict while cumulatively altering the strategic environment (Mazarr, 2015). Seismic surveys, research missions, and cable-related activities are routinely framed as technical or scientific, yet often carry clear geopolitical implications.
Because UNCLOS does not clearly delineate the boundary between permissible research and impermissible interference in disputed seabed areas, states can engage in law-compliant assertiveness. This practice does not seek immediate legal resolution; rather, it aims to normalize presence, gather strategic data, and shape expectations over time. The seabed thus becomes a site of lawfare, where legal interpretation itself functions as an instrument of competition.
Notably, such practices rarely provoke decisive institutional response. International courts and tribunals depend on consent, while political bodies tend to avoid adjudicating subsurface disputes lacking dramatic surface manifestations. Silence, delay, and procedural caution become structural features of governance—further reinforcing the strategic value of the seabed.
The Strategic Implications of Subsurface Governance
From a strategic perspective, the turn toward seabed contestation reflects a broader transformation in international order. As surface-level actions become increasingly constrained by visibility, media scrutiny, and alliance politics, states seek domains where power can be exercised discreetly. The seabed offers precisely such a domain: legally framed, technologically shielded, and politically ambiguous.
For regions such as the Eastern Mediterranean, recognizing the strategic role of the seabed helps explain why legal disputes persist despite extensive surface-level regulation. In these contexts, seabed activity functions not as a precursor to open conflict, but as a substitute for escalation—a means of advancing interests while preserving strategic ambiguity.
Crucially, this dynamic does not signal the erosion of ocean law, but its strategic instrumentalization. UNCLOS remains the language through which claims are articulated and legitimacy is asserted. Yet its vertical limitations allow states to operate at the edge of legality, transforming formal compliance into a source of competitive advantage.
Conclusions: Ocean Law in Three Dimensions
This article has argued that the future of ocean governance cannot be understood through surface-centric legal analysis alone. The seabed represents a domain where law, technology, and power intersect in ways that challenge traditional assumptions about sovereignty and regulation. Through the concepts of vertical sovereignty and legal depth, the analysis has demonstrated that ocean law, while formally comprehensive, becomes strategically permissive as it moves downward.
Recognizing this vertical dimension is essential not only for legal scholarship, but for policymakers and strategic analysts alike. As geopolitical competition increasingly unfolds below the surface, the seabed will continue to function as a silent arena of influence—regulated, yet contested; governed, yet exploitable. Ocean law does not end at the seabed, but it undeniably changes character there. Understanding that transformation is critical to navigating the evolving geometry of maritime power.
References
- Churchill, R. R., & Lowe, A. V. (1999). The Law of the Sea. Manchester University Press.
- Kraska, J. (2011). Maritime Power and the Law of the Sea. Oxford University Press.
- Mazarr, M. J. (2015). Mastering the Gray Zone: Understanding a Changing Era of Conflict. U.S. Army War College.
- Oxman, B. H. (2017). “The Territorial Temptation: A Siren Song at Sea.” American Journal of International Law, 100(4), 830–851.
- United Nations Convention on the Law of the Sea (UNCLOS), 1982.
