As the ability to manoeuvre, map and operate at greater depths increases, critical maritime infrastructure along the seabed – a backbone of national security and resilience – is increasingly at risk in a new age of undersea warfare.
This was the focus of the first blog in our underwater battlespace series, where we provided an overview of the various threats facing subsea infrastructure, described how the domain has become increasingly contested, congested and complex in recent years, and highlighted three broad capability areas that have become increasingly prominent.
Given the scale of the threat to critical undersea cables and the associated challenges facing defence operations – not to mention the threat of crewed and uncrewed underwater vehicles equipped to deliver kinetic and non-kinetic effect – there’s a clear need for autonomous systems and technologies that can deliver enhanced capabilities.
Capabilities that strengthen our ability to prepare for and respond to disruption in the undersea environment, giving us a much-needed advantage over adversaries. The issue is that achieving this advantage is easier said than done.
Exploiting the underwater battlespace
With the subsea domain quickly emerging as a new arena of strategic conflict and competition, how can we engineer the underwater battlespace to our advantage?
Download our new paper to learn about the scale of the subsea threat and why there’s an urgent need for next-generation underwater networking capabilities that can help shape an effective response.
A missing puzzle piece
Amidst the modern landscape, those responsible for defence and national security are facing an important question: how can we counter today’s threats while investing in solutions that will enable us to regain control of the underwater domain?
In short, we need the indicators and warnings to prevent interference or attacks before they happen. This requires sensors and platforms to be ubiquitous, connected (covertly, where necessary) and able to communicate data securely in the theatre of operations in order to accelerate decide and effect functions – fusing this intelligence with a common, integrated operating picture available across surface, air, land and space.
However, underwater communications is still missing a vital puzzle piece. Our current underwater communications technologies – which still rely primarily on radio frequency technology – are not fit for the digital age. They are low data rate, susceptible to the vagaries of the underwater environment, and vulnerable to variations in water temperature, salinity and refraction – particularly at depth.
This means we are facing a critical capability gap that cannot be allowed to persist. At a time of greater strategic tension between nations, this capability gap is recognised both nationally and internationally – requiring a joint industry and government response focused on exploiting the potential of underwater networked communications and subsea operations.
Indeed, national and international trials and exercise programmes are actively pivoting to focus on uncrewed platforms and the associated networked communications requirements. In the vanguard of these is the REPMUS series of exercises led annually by Portugal in the North Atlantic Portuguese exercise areas. Equally, NATO is setting the demand signal through its Allied Underwater Battlespace Mission Network challenge.
A similar emphasis has also be set by the AUKUS nations as captured in the 2025 Maritime Innovation Challenge, which focuses on near real time communications between undersea vehicles in a contested and congested environment. And most recently, the Royal Navy has presented its CABOT requirement, which sets the vision of a digitalised North Atlantic, underwritten by lean crewed, remotely operated or autonomous uncrewed underwater and surface systems.
Next-generation underwater networking
As outlined in the UK MoD’s Maritime Operating Concept and through NATO’s Digital Ocean initiative, next-generation underwater networking addresses needs specific to the modern maritime environment. This capability is critical to delivering a network of cooperating platforms, combining both crewed and autonomous vehicles, that together can deliver collaborative and disaggregated capabilities as part of a true system-of-systems approach to maritime operations.
Such a system must be able to provide seamless connectivity between data and communications interfaces. It must support a range of connections including acoustic (through water), optical (through air and water), RF (through air) and cabled. And it must offer a flexible and adaptable solution that can meet the requirements of the network regarding availability, covertness, bandwidth and reach – among other considerations.
Of course, this is no mean feat, as the underwater domain comes with considerable complexity given the harsh nature of the environment. As well as having to deal with a wide range of bandwidth demands, the networking needs of various underwater autonomous systems, seabed infrastructure and crewed platforms will all be slightly different.
But, progress within industry is being made. For example, at BAE Systems Digital Intelligence we have been able to demonstrate automatically managed data routing across a multi-node network comprising a mixture of all-through-water, air-water interface, cabled, and through-air RF links – testing scenarios that simulate the needs of mine countermeasure and anti-submarine warfare operations.
So, industry is responding to the current threat landscape through the development of underwater platforms and communications technologies. But there is still much more to be done. Stay tuned for the next and final blog in this series where we outline the next step to building a stable and secure subsea environment.