1 For centuries, maritime power has been expressed through the ability to project naval forces, to protect or disrupt oceanic trade routes, and to maintain a strategic presence at sea. This capacity “to do and to make others do,” in Raymond Aron’s terms, rested on military power, conditioning economic or scientific power. It was supported by the ability to map space. Over the course of the twentieth century, this notion of maritime power became increasingly complex as new actors operated in oceanic space. It now encompasses more diverse domains and mobilizes domain-specific  [1], each arena of maritime action requires its own form of capital, whether technical, human, or financial. Maritime power is thus shaped by a combination of levers: investments provide operational superiority within specific arena, and each state possesses a distinct palette of spheres of power—sometimes more economic, through merchant fleets and ports; sometimes naval, through surface and submarine fleets; sometimes scientific. While maritime power is multifaceted, it nonetheless retains a foundational core rooted in the capacity to act and to know who is acting.

2 The territorialisation of the sea, the multiplication of means of knowledge about the ocean and the activities that take place within it have altered the very paradigm of power. On the first point, the evolution of international norms—most notably the United Nations Convention on the Law of the Sea (UNCLOS), adopted in 1982 in Montego Bay—has produced a radical shift. It defined maritime zones under state jurisdiction or sovereignty, establishing exclusive economic zones (EEZs) and territorial seas. In parallel, other instruments developed under the auspices of the International Maritime Organization (IMO) have assigned new responsibilities to states in matters of maritime surveillance and search and rescue. De facto, the ocean is no longer merely a space of free circulation in which power is exercised through presence alone; it has become a space in which observation and management are essential. This echoes with the two other changes mentioned above.

3 Deepdiving into the multiplication of means of knowledge, one has to highlight innovation. Technological innovation—both in so-called in situ sensors, deployed on and in the water (such as buoys or drones) or along coastlines, and in satellite-based sensors—has made scientific understanding of the ocean increasingly precise, while also enabling more accurate monitoring of economic activities. Understanding maritime activities in real time has thus become both possible and strategic. From their collection to their processing, data constitute a keystone of this paradigm shift. They are an essential parameter for ensuring sovereignty, security, and control of the sea. In this context, the question is no longer solely how to maintain a physical presence at sea, but rather how to use and optimize digital technologies in order to strengthen that presence and maximize the resulting capacity for action. Far from being simple tools of management or decision support, data have thus become genuine vectors of power.

Data as instruments of power

4 Data make it possible to construct an image—more or less immediate, depending on the available means—of what is occurring at sea, notably by delineating the digital wake of vessels; that is, the set of digital information associated with them, enabling to retrace their past and current trajectories and, in some cases, to anticipate their future ones. If power implies the ability to impose one’s choices upon others, it rests both on knowledge of those “others”—their activities, intentions, strategies, strengths, and weaknesses—and, as in many other fields, on mastery of geography and of the evolving physical characteristics of the ocean. Such detailed knowledge of the environment remains a key coercive capacity of action. Both environmental data and navigational data therefore prove indispensable.

5 However, these two major categories of data form a highly heterogeneous ensemble, relying on diverse communities, national or international actors, systems and platforms, as well as a variety of channels. The core difficulty therefore lies in the ability to structure this ensemble without betraying its inherent complexity. This data also span a broad spectrum: physical, chemical, and biological data, but also logistical, declarative, and behavioral data. They enable to monitor vessels and their cargoes. They can provide information about their behavior and, through more exploratory means, their intentions based on analysis of their digital wake. Cross-referencing data facilitates the identification of weak signals, the characterization of vulnerabilities, and the detection of anomalies. For instance, if an industrial fishing vessel—normally required to transmit its position—ceases to do so in an area where the presence of a protected fish species has been reported, the correlation of data raises questions regarding its intent: is it seeking to conceal itself? And from whom? The same line of questioning may apply to a cargo vessel adopting similar behavior in the vicinity of submarine cables.

6 This intrinsic complexity of maritime data also calls for consideration of the diversity of logics governing their collection, updating, storage, and analysis, which vary according to disciplines, projects, and institutions—without even mentioning the differences in approaches across national scales. One may also point to the heterogeneity of scientific and environmental data, which track physical parameters—such as temperature and salinity—chemical parameters—such as pollution or ocean acidification—and biological parameters—such as species migration. Scientific data, although increasingly supported by dense networks of in situ and satellite sensors, still allow only a partial understanding of the ocean. To this diversity of data types and collection systems—buoys, vessels, drones, remotely operated vehicles, satellite sensors, Automatic Identification System (AIS) data—are added a multiplicity of channels and platforms, generating just as many challenges in terms of transmission—bandwidth, security, latency—as well as format—encoding, encryption—and reliability. While maritime activity monitoring tools provide a relatively accurate picture of the maritime situation, significant challenges remain for the massive volumes of data related to ocean physics.

7 These technical aspects of data sharing only constitute the first stage of maritime data management. It is then necessary to establish protocols for embedding and articulating this data in order to serve specific purposes. Can, for example, measurements of oxygen content in surface waters be correlated with the most recent passages of vessels identified through their AIS data (which relay their position)? Data fusion involves combining data of different natures and sources not only to strengthen the reliability of processed information, but also to superimpose data relating to sometimes very different domains into a coherent and exploitable whole. The processing of these flows relies on heavy technical infrastructures, in which artificial intelligence (AI) and machine learning play a key role for this fusion to be relevant, rapid, and reliable.

8 Technical challenges are therefore diverse in nature, yet they converge toward a single objective: to combine collected information in order to produce a detailed portrait of maritime activity with the lowest possible latency. The goal of real-time processing—entailing not only rapid data circulation but also reliability and readability—has become imperative, as it is embedded in a broader compression of time that now affects all domains. The speed of data acquisition and analysis conditions responsiveness to threats or sudden changes. Missile detection, pollution identification, or maritime route optimization all depend on such mastery of time. Information becomes a weapon once it is reliable and immediately exploitable. Data can thus respond both to the suddenness of war and to the detection of weak signals of natural disasters or malicious behavior by certain maritime actors.

9 The “five V’s” of Big Data encapsulate the challenges of collection and storage (volume), circulation (velocity), fusion (variety), analysis and cross-checking (veracity), and ultimately use (value) associated with the implementation of a coherent maritime data strategy. The challenges related to interoperability among collection systems, information reliability, and data confidentiality are yet immense. Systems such as AIS, although useful, may be circumvented by private or public actors seeking to conceal their activities. For data to become a genuine instrument of maritime power, it is therefore essential to strengthen intra-state cooperation through the development of robust security protocols and—paradoxical as it may seem—to foster a culture of data sharing among states.

Aligning actors at the national level: an indispensable step toward strategic coherence in maritime data

10 Mastery of one of the arenas—one of the chessboards that together constitute the mosaic of maritime power, in Yan Giron’s understanding [2]—requires investments whose financial scale often makes partnerships necessary. This partnership-oriented approach must first be expressed within the state itself, among services and administrations. Because both military and civilian actors operate at sea, and share maritime chokepoints, maritime space is described as non-segregated. Consequently, maritime data must also circulate between civilian and military administrations, between scientific communities and public authorities. The concept of Maritime Domain Awareness (MDA) constitutes a response to this challenge, by merging navigational data. Defined by the International Maritime Organization (IMO) as “the effective understanding of anything associated with the maritime domain that could impact safety, security, the economy or the environment” [3], MDA requires overcoming institutional silos, harmonizing formats, and pooling resources. It is deployed primarily at the national level. However, as Jérémy Bachelier and Philippe Boulanger point out, MDA “raises issues of trust, organizational cultures, interests, bureaucratic routines, or political considerations, which may diverge and generate difficulties in data sharing due to confidentiality, sovereign prerogatives, or commercial concerns” [4].

11 The alignment of navigational data—combined through MDA—and environmental data—which are themselves subject to fusion through initiatives such as Mercator Ocean International—remains a challenge of greater magnitude. Environmental data are already governed by numerous protocols designed to foster exchanges, notably through the FAIR data-sharing principles: Findable, Accessible, Interoperable, and Reusable. These principles follow the open data movement—focused on public data—and, subsequently, open science. Yet physical ocean data enable the analysis of the evolution of a given area, oceanic layers, dilution conditions for submarine nuclear deterrence, and, conversely, the granularity sharpening of certain navigational data. They therefore constitute both a challenge in terms of data volume and processing—through modelling—and a central lever of knowledge.

12 To enhance capabilities for detecting threats, illicit activities, or managing risks in critical transit zones, data coherence relies on the establishment of an inter-community data culture—scientific, administrative, military, and economic—at the national level. Such a project requires an inventory of all data sources, platforms, and technical challenges, as well as the implementation of a structured approach built around a keystone: the adoption of shared principles. These common principles are far from neutral, as they rest upon a political vision of data—for example, privileging data accuracy and verification over immediacy, or speed over sheer volume. The sensitivity of data and vulnerability of systems must also be taken into account, particularly in light of the expanding cyberattack surface associated with data-sharing platforms.

Challenges of interstate cooperation, data sharing and data fusion

13 Data sensitivity appears to be the most delicate issue. If data sharing is already difficult to achieve at the infra-state level, it proves even more complex between states. Even in the case of trust and interdependence among actors, interstate cooperation often takes the form of ad hoc, limited, and targeted data exchanges. The systematization of data sharing is a lengthy process, both technically and politically. Yet the surveillance of maritime approaches depends upon it.

14 In the face of compressed decision-making timelines and a fragmented geopolitical environment, it has become necessary for France and the European Union (EU) to articulate intellectual and material tools to become digital maritime powers. Such a transformation would address the rise of hybrid forms of conflict—difficult to detect and manage—which increasingly threaten freedom and security of navigation. Because following vessels’ digital wakes is crucial, the EU develops data-sharing capacities, such as the Common Information Sharing Environment (CISE) initiative [5], which provides tools and mechanisms for data exchange among administrations of Member States. This approach is indispensable at a time when sanctions imposed on Russia are being circumvented, notably through a disparate set of vessels forming a so-called “ghost fleet.” The establishment of a European Maritime Domain Awareness would thus constitute a lever for weakening the financing of the Russian war effort.

15 Through the parallel development of scientific data sharing systems and CISE, the EU builds levers of maritime power without yet fully controlling their implementation vectors. Member States continue to jealously retain the majority of competencies related to maritime power. This raises the question of the appropriate scales at which digital maritime power should be structured. Since the construction of such power necessarily relies on partnership and cooperation, it may well be through the arena of data that the EU can act as a spearhead for the national maritime powers within it.

Building partnerships and cultural bridges between public and private sectors

16 The adoption of a structured strategy to align maritime data at the national or European level requires combining public and private data, sensitive and open data, industrial secrecy and defense confidentiality, and articulating platforms and systems from both technology and maritime communities. The stakes are considerable, yet unavoidable, as collaboration between private and public actors becomes crucial in a geopolitical context marked by fragmentation and the growing hybridisation of conflicts and actors. Such partnerships presuppose mutual trust, as well as transparency in data governance and sharing, thus requiring careful design.

17 The maritime world can act both as a contributor—through data collection via onboard sensors and data-sharing—and as a decision-making actor in matters related to security. As Tancrède Wattelle emphasizes [6], as threats at sea become increasingly complex and decision-making timelines more compressed, the distribution of data collection between public and private sectors within enhanced cooperation frameworks could lead to decentralise certain maritime security decisions. One may imagine commercial vessels being exposed to a growing range of threats. Cyber threats, missile attacks, and piracy could intensify in the current context, affecting several key zones simultaneously and necessitating continuous adaptation by the private sector. Indeed, that would call for short-notice decision making, enhancing decentralisation of maritime security, to a certain extent. At the heart of public-private partnerships and cooperation lies trust and a common data culture.

18 Such cooperation would help sustain freedom of navigation. Detecting adversarial maritime digital wakes—or, conversely, being able to reduce one’s own as much as possible to ensure a degree of stealth—will prove decisive.

19 At the same time, public actors will need to build bridges with technology and digital communities. It is essential, in order to ensure data interoperability, high-quality analysis through advanced artificial intelligence systems, and visualization for decision support. Cooperation with these sectors, as well as with the space sector, underpins real-time situational awareness, a structuring element of maritime operational capacity.

20 Establishing a shared language constitutes a first step, the difficulty of which should not be underestimated. Technology and maritime communities are accustomed to operating in closed, complex, and highly technical environments. While they share a common principle of freedom and certain elements of vocabulary drawn from the lexicon of navigation, they nevertheless reason primarily on the basis of the environments in which they operate. It is particularly important to emphasize that, whereas the maritime sector thinks through the sea, the digitization of this sector anchors security issues far from the ocean, within continental spaces: cybersecurity is built where data centers and human operators are located— predominantly on land.

21 The alignment of maritime data—whether environmental, military, or commercial—constitutes a challenge of considerable magnitude. A key step in the construction of digital maritime power, this endeavor rests upon cooperation between science, the private sector, public authorities, and the military sphere. Establishing systems for the collection, sharing, and analysis of maritime data that articulate the value of this data, their volume, their sensitivity, and their vulnerability, in order to build reliable systems and inform real-time decision-making, represents an indispensable strategic lever for maritime powers. This must be grounded in careful consideration of security, confidentiality, and trust issues. Ultimately, only a state capable of controlling maritime data will be able truly to assert its sovereignty at sea, and thereby lay claim to genuine digital maritime power.