© Supplied by Global Underwater Hu The UK government’s 2025 Strategic Defence Review made it very clear that our underwater domain is more vulnerable – and more strategically vital – than ever before.
The threats to critical subsea infrastructure – from undersea cables carrying data to those carrying power from offshore energy assets – are very real, present and persistent.
In recent years, geopolitical tensions have moved from land borders and airspace into the depths of our oceans. For a maritime nation like the UK, which relies heavily on subsea connectivity and energy, the implications are serious.
Yet amid this threat landscape lies a critical opportunity – if the Ministry of Defence (MoD) is willing to seize it.
A real and growing threat below the surface
The underwater domain has long been overlooked in terms of national security, often relegated to niche defence programmes or the periphery of naval operations.
But today, our global subsea network of data cables, offshore renewable energy, oil and gas pipelines, and strategic maritime routes are under increasing surveillance – and potentially at risk of sabotage – from both state and non-state actors.
This shift in threat is driven by the increasing accessibility of underwater technology. Autonomous underwater vehicles (AUVs), remote sensors and subsea drones – once the preserve of elite military programmes – are now commercially available and widely deployed.
In the wrong hands, these technologies can be weaponised. Protecting them demands not just vigilance but technical superiority.
© Supplied by Royal NavyCommercial sector: an untapped ally in defence
Defending our underwater assets cannot rest solely on the shoulders of traditional defence procurement or legacy naval platforms. The pace of change is simply too fast. Threats evolve in months, not years, while defence acquisition cycles can take a decade. This disconnect is not only unsustainable – it is dangerous.
This is where the UK’s commercial subsea sector can, and must, play a vital role.
Global Underwater Hub (GUH), the leading trade and industry body for the UK’s £9billion subsea sector, represents a vibrant, innovation-driven supply chain already delivering solutions to complex underwater challenges.
This supply chain spans marine robotics, AI-enabled surveillance, energy transition technologies, and cutting-edge offshore infrastructure services. Many of these technologies are not just defence-relevant, they are defence-ready.
Unfortunately, this capability has too often been overlooked by defence planners. But, in the interests of our defence and energy security, this must change and quickly.
Strategic partnerships already in place
The good news is that the building blocks for collaboration already exist. GUH has worked to forge critical partnerships across government and defence, including with the Defence and Security Accelerator (DASA), the UK Defence Solutions Centre (UKDSC), the London Tech Bridge, and operationally with the Royal Navy.
These collaborations demonstrate what’s possible when industry and defence align around a common goal. Through these frameworks, GUH has helped identify commercially available technologies with the potential to be adapted for defence use without the need for prolonged R&D cycles. In many cases, these solutions are already in deployment for offshore energy, subsea inspection, environmental monitoring, and autonomous operations.
However, these partnerships must go further, faster, and deeper. The scale and immediacy of the underwater threat now demands a more agile and proactive response from the MoD.
Unlike previous decades, where defence technology was often developed in silos with long gestation periods, today’s threats allow no such luxury. In the underwater environment, we are already in a live and contested space.
Russia, China, and other actors have shown increasing interest in our subsea cables and offshore installations. Hybrid threats, from cyberattacks on subsea data systems to physical interference with energy infrastructure, are now plausible scenarios. In response, the MoD must pivot to a model that values adaptability, speed, and cross-sector integration.
This requires a mindset shift. Instead of viewing the commercial sector as a supplier of last resort, defence must begin to see it as a primary innovation partner. This is especially true in the underwater domain, where GUH members operate at the cutting edge of what is technically feasible.
© Andy Buchanan/PA WireAn industry ready to respond
The subsea industry already leads in fields such as autonomous systems, environmental sensing, structural integrity, and remote intervention. These technologies are critical to both defending infrastructure and understanding the underwater battlespace.
GUH has a unique and holistic visibility of this capability. We understand not only which companies are developing what technologies, but also their readiness level, deployment history, and potential for rapid adaptation to defence use cases.
By working directly with GUH, the MoD can dramatically shorten its innovation cycle. We can help defence identify mature technologies, accelerate trials and evaluations, and ensure that solutions are deployed where and when they’re needed most.
Meaningful collaboration with the commercial underwater sector is no longer optional, it is essential.
And GUH stands ready to lead that effort. But collaboration must go beyond workshops and white papers. It must involve sustained engagement, rapid procurement pathways, and joint risk-sharing models that enable the fast integration of commercial technologies into defence operations.
The MoD must be prepared to trust in the capability of the UK’s subsea sector. This is not about diluting defence standards or outsourcing responsibility. It is about leveraging the full spectrum of national capability to meet a national challenge.
A strategic imperative
The underwater threat to our national infrastructure is not only strategic – it is existential. A single successful attack on a key subsea cable or offshore energy node could have cascading effects on our economy, security, and society.
Responding to that threat requires new thinking. It demands that we view the UK’s subsea supply chain not just as an economic asset, but as a national security resource.
The 2025 Strategic Defence Review presents a timely opportunity to institutionalise this perspective – to place underwater defence at the heart of our national strategy and to embed collaboration with the commercial sector into the DNA of how we protect our interests.
At GUH, we are ready to act. The question now is: will the MoD move with the urgency this challenge demands?
