A fundamental capability requirement is improving the surveillance of infrastructure which, as previously noted, is extensive in nature and frequently located in remote and hostile environments. A range of solutions have been implemented, or are under development, to alleviate these challenges. These include the use of satellite imagery to track the activity of potential hostile surface vessels, the use of autonomous USVs to undertake remote surveillance of the seabed and the use of fixed-point sensors to detect anomalies. The pace of technological development is rapid. For example, in November 2024, Thales announced an agreement with another French company, FEBUS Optics, to utilise the latter’s distributed fibre optic sensing (DFOS) technologies to enhance the functionality of its existing BlueGuard sonar system. DFOS can be used to monitor the water space around the entire length of a piece of CUI, detecting acoustic signals generated close to the infrastructure being monitored.
Another important example of technological development is the down-scaling of sonar technologies to integrate with the new generation of uncrewed platforms. In December 2025, SEA, part of the British Cohort group, revealed it had been awarded a multi-million-pound contract to supply 22 of its KraitArray undersea sensing systems to Liquid Robotics, a Boeing Company, for integration into the company’s Wave Glider uncrewed surface vessel (USV). Described by the company as delivering high-end, passive acoustic detection performance in a compact, modular form, KraitArray – and similar compact sonars – offer the prospect of significantly improving the ability of uncrewed platforms to provide enhanced intelligence and maritime domain awareness in support of CUI protection.