Governments and defence contractors are shifting money and technology toward protecting cables, pipelines and power links on the ocean floor, creating a nascent market for underwater surveillance and autonomous systems.
The change follows a string of incidents and broader worries about hybrid warfare, where attacks can mix sabotage, cyber operations and economic pressure. Katja Bego, senior research fellow at Chatham House, said, "It's the changing threat environment that's brought this to the fore." She added that the scale of undersea networks matters because, "Our whole economy is built on top of this."
Subsea infrastructure is vast: TeleGeography reports more than 1.5 million kilometres of submarine communications cables in service globally as of early 2026. That network sits alongside oil and gas pipelines and a growing web of subsea power lines that link offshore wind and regional grids, all of which planners now see as vulnerable.
At the same time, advances in artificial intelligence, drones and autonomy are enabling new approaches to monitoring those assets. Shipbuilder Fincantieri announced plans in July to acquire majority stakes in four companies for around 600 million euros ($689 million) to expand into underwater and surface drones, marine surveying and subsea communications. Pierroberto Folgiero, Fincantieri's chief executive, called underwater telecommunications "the real enabler of this new ecosystem," and described future surface vessels acting as "motherships" that coordinate networks of vehicles across the water column.
Large defence groups including Thales and smaller technology firms are already moving into sonar, anti-submarine warfare, mine detection and autonomous underwater systems. Germany's Euroatlas is developing an autonomous vehicle called GrayShark that can be sent to a mission area and operate without continuous human control. Verineia Codrean, Euroatlas's chief strategy and partnerships officer, said GrayShark can report discoveries and wait for an operator before further action.
Codrean argued the shift is partly a problem of scale: "It is virtually impossible to cover the entire ocean," she said, pointing out that frigates, submarines and patrol aircraft are too costly and scarce to provide constant presence across vast seabed corridors. She also warned that autonomous fleets will prompt countermeasures, noting, "What we are building, so are our non-allies or our enemies building as well."
Executives and researchers describe the current moment as catch-up after decades of underinvestment. Defence companies are realigning strategy and capital to supply the sensors, vehicles and networks that militaries and energy and telecom operators now want to secure critical undersea infrastructure.
