The race to secure the seabed is no longer confined to submarine warfare. It is becoming a competition to protect the infrastructure that supports the global digital and energy economy.
Submarine telecommunications cables, offshore energy networks, electrical interconnectors and seabed data routes now form a critical layer of national infrastructure. According to NATO, more than 95 percent of global internet traffic passes through undersea cables. As recent incidents in the Baltic Sea and the North Sea demonstrated, those networks are increasingly exposed to disruption, sabotage and strategic pressure.
What is changing is not simply the level of vulnerability, but the scale of surveillance now being deployed beneath the surface. Major maritime powers are investing heavily in distributed underwater surveillance architectures combining seabed sensors, autonomous underwater vehicles, surface relays, satellites and data-fusion centers. The objective is no longer occasional monitoring. It is persistent underwater awareness.
Yet despite rapid advances in sensors and autonomous systems, no country has fully solved the central problem of undersea surveillance: turning fragmented streams of underwater data into a coherent operational picture that can support rapid decision-making.
Underwater surveillance is becoming a distributed network
For decades, seabed monitoring relied primarily on specialized naval platforms operating around strategic chokepoints and military infrastructure. That model is no longer sufficient.
Today’s maritime powers are attempting to build distributed surveillance architectures capable of maintaining persistent coverage across vast maritime areas, including exclusive economic zones extending across multiple oceans.
This evolution begins with fixed acoustic sensor networks. Originally developed during the Cold War, these systems rely on passive seabed sensors designed to monitor strategic transit corridors, offshore energy infrastructure and submarine activity. The United States retains a significant advantage in this area after decades of investment in integrated ocean surveillance and long-range undersea detection systems.
But fixed networks alone cannot cover the scale of today’s maritime infrastructure challenge. France illustrates the problem particularly well. Thanks to its overseas territories, Paris controls the world’s second-largest exclusive economic zone, stretching across the Atlantic, Pacific and Indian Oceans. Monitoring such dispersed maritime space requires a far more distributed model built around autonomous systems, robotic platforms and mobile seabed surveillance capabilities.
Australia faces an even more extreme version of the same operational problem. Canberra has invested heavily in long-endurance autonomous underwater vehicles capable of operating across enormous maritime distances with limited support infrastructure. These programs are intended not only for infrastructure protection, but also for underwater intelligence gathering and seabed mapping.
The United Kingdom is pursuing a different approach focused on protecting North Atlantic infrastructure and offshore energy networks. The commissioning of the specialized vessel RFA Proteus reflects London’s effort to field platforms capable of supporting long-duration seabed surveillance and intervention missions.
Across all of these approaches, the doctrinal shift is becoming increasingly clear. The key capability is no longer the individual platform itself, but the ability to connect multiple layers of sensors, autonomous systems, surface relays, satellites and intelligence networks into a single operational architecture.
Underwater surveillance is gradually evolving into a system-of-systems challenge.
Underwater communications remain the main technological bottleneck
Despite rapid progress in autonomous underwater vehicles and seabed sensing technologies, the underwater environment remains fundamentally hostile to communications.
Unlike air or space systems, radio waves do not travel efficiently through seawater. Most underwater architectures therefore rely on acoustic communications, which remain slow, bandwidth-limited and vulnerable to environmental interference.
This changes the operational logic of underwater drones entirely. Unlike aerial drones, autonomous underwater vehicles generally cannot stream large amounts of data continuously. In many cases, data must be recovered intermittently through surface relays, buoys or specialized support vessels.
As a result, the satellite constellation model cannot simply be replicated underwater. Some industrial actors occasionally use the expression “underwater constellation,” but the term remains largely conceptual. Existing architectures still depend on fragmented communications, intermittent data recovery and heavy logistical support.
Energy endurance represents another major limitation. Long-endurance autonomous underwater vehicles require large battery capacity, complex recharge cycles and regular maintenance. Maintaining persistent underwater coverage therefore becomes extremely expensive, particularly for countries operating across vast exclusive economic zones dispersed over multiple oceans.
The United States and Australia are both investing heavily in this endurance problem. In the Pacific, where distances make continuous naval patrols impractical, autonomous systems must operate for extended periods while retaining at least limited communication and intelligence-sharing capability. This is pushing industry toward hybrid architectures combining onboard autonomy, improved energy management and intermittent data retrieval.
Even fixed seabed sensors create a hidden logistical burden. Networks must be inspected, recalibrated and protected against environmental degradation. That requires specialized vessels that are expensive to operate and difficult to maintain continuously on station.
These constraints explain why persistent undersea awareness remains far more difficult than simply demonstrating an autonomous underwater drone.
Russia and China are accelerating the undersea competition
Russia and China are playing a major role in accelerating Western investments in seabed surveillance, although their approaches differ significantly.
Western concerns regarding Russia focus primarily on hybrid pressure against critical infrastructure. Multiple analyses from the Royal United Services Institute argue that Moscow increasingly views undersea cables and offshore energy infrastructure as potential tools of strategic leverage.
Russia also retains longstanding expertise in deep-sea operations and specialized undersea warfare missions. Activity observed in the Arctic and North Atlantic continues to fuel concerns regarding seabed mapping, cable surveillance and covert underwater operations targeting critical infrastructure.
China is pursuing a broader and more industrialized model centered on distributed underwater surveillance at scale. Beijing is gradually developing a multi-layered architecture combining autonomous underwater vehicles, ocean-floor mapping, specialized survey ships and underwater sensing networks. Several American assessments argue that these capabilities support both civilian scientific missions and long-term military objectives.
Reuters also documented Chinese ocean-floor mapping campaigns in strategically sensitive areas of the Pacific.
For Western navies, the challenge is no longer limited to detecting submarines. It increasingly involves monitoring a dense ecosystem of underwater infrastructure, autonomous systems and commercial maritime activity across enormous maritime spaces.
The main weakness remains command fragmentation
The hardest problem in seabed protection is no longer detecting an anomaly. It is determining who receives the alert, who validates the incident, who shares the data and who has the authority to act.
This fragmentation is particularly visible across Europe. NATO has expanded coordination mechanisms dedicated to critical undersea infrastructure protection and launched several new cooperation structures.
The European Union is simultaneously developing new frameworks for cable and infrastructure resilience.
But operational responsibility remains divided among navies, coast guards, civilian authorities, offshore energy operators, cable companies and private maritime-security actors. This creates major complications for data fusion and threat assessment. Some information belongs to military intelligence networks, while other data is controlled by private infrastructure operators.
False positives create another layer of complexity. Scientific activity, commercial shipping, offshore construction and industrial fishing can all produce signatures that are difficult to distinguish from hostile activity. In a noisy acoustic environment, attribution often remains uncertain.
Large exclusive economic zones make persistent surveillance even more difficult. France, Australia and the United States must all monitor enormous maritime spaces with dispersed assets and significant logistical constraints.
As a result, major maritime powers are gradually building persistent undersea awareness architectures, but none has yet achieved a fully integrated command system capable of combining military, civilian and commercial underwater surveillance into a unified operational picture.
Building persistent underwater awareness
The seabed is becoming a strategic infrastructure domain alongside space and digital networks.
This transformation is pushing maritime powers toward increasingly distributed surveillance architectures combining seabed sensors, autonomous underwater vehicles, artificial intelligence, surface relays and multi-agency fusion centers.
But the most important limitations remain less visible than the drones themselves. Underwater communications remain constrained, maintenance is expensive, endurance is difficult and command architectures still struggle to integrate data originating from fundamentally different actors and networks.
The next phase of seabed competition will therefore not simply depend on deploying more underwater sensors. It will depend on building operational architectures capable of transforming fragmented underwater data into persistent maritime awareness.
