The race for quantum advantage is no longer confined to theoretical physics labs or science fiction; it is playing out in real time on – and beneath – the global stage. In the maritime domain, the potential of Quantum Technologies (QT) to transform navigation, communication and situational awareness is profound. At NATO’s Centre for Maritime Research and Experimentation (CMRE) in La Spezia, Italy, a new frontier is being explored – where photons replace cables, quantum states replace classical algorithms and the ocean becomes not just a theatre of operations, but a laboratory for some of the most advanced sensing technologies in development today.

QUANTUM RESEARCH FROM NATO STRATEGY

CMRE’s quantum research programme is a direct response to NATO’s 2030 Initiative, which aims to preserve the Alliance’s technological edge in the face of rapid innovation. As emerging and disruptive technologies reshape global security, QT offers a strategic opportunity and potential threat. An adversary’s breakthrough in quantum sensing, communication or computation could compromise NATO’s technological advantage, making it imperative to lead in this domain.

To meet this challenge, CMRE established a structured and high-impact Programme of Work (PoW) in Quantum Technologies in 2019. This effort is grounded in a dedicated CMRE Quantum Strategy, further refined through collaborative workshops, including the NATO Science & Technology Organization’s (STO) 2023 Quantum Technologies Workshop in Turin, Italy. These gatherings brought together scientists, defence professionals and policymakers to assess quantum challenges and sketch out a coordinated path forward.

The CMRE QT PoW is built around three interwoven research streams: Quantum Communications and Optics, Quantum Computing for maritime and underwater applications, and Quantum Positioning, Navigation and Timing (QPNT). Each stream addresses core defence needs, while remaining closely integrated to ensure holistic, operationally relevant solutions.

SECURING THE SEAFLOOR

The ocean environment presents unique challenges to secure communication. As quantum computers edge closer to reality, the cryptographic foundations of today’s digital infrastructure face increasing vulnerability. Underwater communications are particularly exposed, where bandwidth, energy and hardware constraints limit the application of classical cryptographic defences.

One promising solution is Underwater Quantum Key Distribution (UQKD), a field in which CMRE has been conducting experimental and theoretical research since 2019. UQKD enables the exchange of cryptographic keys via individual photons, exploiting quantum properties that make the system inherently secure against eavesdropping. Unlike Post-Quantum Cryptography (PQC), which relies on complex algorithms and heavy processing, UQKD can be implemented on custom-designed, low-power hardware – ideal for constrained maritime environments.

CMRE’s Quantum Lab is focused on building practical, field-ready UQKD systems that can operate at speed and depth. Developing such a system requires not only precision engineering, but also a deep understanding of how light behaves underwater. To that end, CMRE is investigating the effects of scattering, absorption and turbulence on photon transmission, combining classical and quantum optics research to lay the scientific groundwork for operational capability.

Though still in its early stages, UQKD is advancing quickly. Terrestrial quantum communication systems are moving toward commercial deployment, and CMRE is ensuring that similar breakthroughs will soon be possible in underwater contexts, helping NATO stay ahead in the security of subsea infrastructure and missions.

NAVIGATING WITHOUT GPS: A REVOLUTION

Of all quantum-enabled technologies, Quantum Positioning, Navigation, and Timing (QPNT) may be closest to practical deployment. As reliance on satellite navigation grows, so too does the vulnerability of systems that depend on it. In environments where GPS signals are unavailable or compromised – such as deep underwater or in contested zones – QPNT offers a powerful alternative.

CMRE initiated its QPNT research in 2022 and has since made it a focal point of the Quantum Lab. These efforts include the use of Quantum Magnetometers, which detect subtle variations in Earth’s magnetic field to support inertial navigation. In 2024, CMRE participated in the MAG24 sea trial and led the QUESTOR24 mission aboard the Coastal Research Vessel Leonardo, conducting at-sea testing of these cutting-edge sensors.

The promise of QPNT lies in its capacity to enable long-duration, signal-independent navigation. In the next five to 10 years, it is expected that quantum sensors will enable submarines, autonomous vehicles and manned platforms to navigate accurately without recourse to external signals – a capability of immense strategic value. CMRE is uniquely positioned to contribute to this emerging field thanks to its operational assets, maritime expertise and commitment to real-world experimentation.

QUANTUM ALGORITHMS FOR MARITIME USE

Quantum Computing is often regarded as the most transformative – and elusive – of all quantum technologies. Its potential to solve problems deemed intractable for classical machines could reshape areas ranging from cryptography to materials science. While many of its applications remain hypothetical, CMRE has taken proactive steps to explore its relevance to the maritime domain.

In 2024, the centre launched a dedicated initiative to develop Quantum Computing expertise tailored to underwater and naval scenarios. The initial focus lies in navigation, where quantum algorithms – particularly Quantum Physically Informed Neural Networks – are being investigated for their ability to improve models of motion, fluid dynamics and environmental prediction.

Although the timeline for deployable quantum computers remains uncertain, early experimentation is essential to ensure that NATO is ready to exploit their capabilities as they mature. CMRE’s efforts are building foundational knowledge, nurturing skills and identifying key maritime applications where quantum computing could provide a decisive edge.

PREPARING FOR A QUANTUM FUTURE

As NATO faces increasingly complex threats across multiple domains, Quantum Technologies represent both a strategic imperative and a remarkable opportunity. CMRE’s research, rooted in operational relevance and rigorous scientific methodology, is helping to turn promise into practice. Whether enabling secure underwater communication, resilient navigation or advanced computation, the centre’s quantum work ensures the Alliance is not only reactive, but proactively shaping its future capabilities.

The seas have always demanded innovation – from ancient navigation by stars to sonar and satellite. Today, with quantum technologies on the horizon, CMRE is helping to chart NATO’s course into this next great era of maritime technology. The quantum tide is rising, and the Alliance is ready to ride the wave.

This article was first published in the June 2025 edition of the NATO Communications and Information Agency’s ‘NITECH’ magazine