Russian activity in the High North demonstrates why data matters. Sub-threshold ‘grey zone’ actions extend to matters as seemingly innocent as fishing and research, with Russian vessels operating near military training areas, energy installations, and undersea infrastructure while retaining the protections of civilian activity. Unusual tracks, gaps in automatic identification system transmissions, or non-standard surveillance equipment may indicate intelligence collection, coercive signalling, or nothing hostile at all. The uncertainty is itself strategically useful.
The United Kingdom (UK) therefore faces a problem of discrimination as much as detection. It is not enough simply to know that a vessel passed over a cable or that a sonar has found an object. Decision-makers must determine whether something has genuinely changed; how confident they are in that assessment; and whether the evidence justifies inspection, attribution, or a military response.
Survey turns data into evidence
Gen. Sir Gwyn Jenkins, First Sea Lord, has presented the ‘Hybrid Navy’ as a force in which crewed and uncrewed systems increase the Royal Navy’s mass, reach, and survivability. Atlantic Bastion, its North Atlantic expression, envisages a layered network of vehicles and sensors detecting hostile sub-surface activity. This is a sensible response to a distributed threat: a frigate cannot guard every cable, pipeline, or offshore installation.
The difficult step comes after collection: recognising a new object, anchor scar, disturbed sediment, or exposed cable. This requires a correctly positioned baseline collected to a hydrographic standard. Repeat data must be sufficiently comparable to distinguish real change from errors in navigation, sensor geometry, sound velocity, tides, seabed mobility, or processing. Artificial Intelligence (AI) can flag anomalies, but it cannot make poorly controlled surveys comparable or explain uncertainty to an operational commander.
Hydrography is therefore a crucial component of the Hybrid Navy’s decision architecture, not just a supporting service. A nation able to detect, document, and communicate seabed interference reduces the advantage an adversary gains from ambiguity. Surveying does not eliminate plausible deniability, but it narrows the space in which deniable action can operate.
Capacity without surrendering judgement
In Britain, the maritime industry is assembling the platforms, navigation, sensors, autonomy, and processing needed for this task. The proposed acquisition of Exail by Thales offers a conspicuous example of the consolidation of this undersea survey stack. Project CABOT’s proposed ‘Contractor Owned, Contractor Operated, Naval Oversight’ model could similarly bring commercial vessels, autonomous systems, and experienced operators into Atlantic Bastion more quickly than the Royal Navy could generate them alone.
Contracting, however, must not hollow out the state’s intelligent-customer function. Naval oversight cannot mean simply receiving a processed contact report. His Majesty’s (HM) Government should retain the competence to set survey standards, audit algorithms, assess uncertainty, protect data, and recognise when a commercial task has become an inherently military one. This is especially important as the UK’s marine-geospatial skills pipeline remains fragile. Indeed, the Royal Institution of Chartered Surveyors has warned that shortages and inadequate educational provision constrain the protection of undersea infrastructure.
A specialist seabed reserve
The required expertise for undersea surveying already exists, but much of it sits outside defence: in the UK Hydrographic Office, universities, ports, offshore energy companies, equipment manufacturers, and survey contractors. A Royal Naval Volunteer Reserve (RNVR)-style hydrographic reserve could connect that civilian community to naval operations.
The historical reference needs care. Established in 1903, the RNVR trained civilians for naval service before merging with the Royal Naval Reserve (RNR) in 1958. The useful principle is not the recreation of a separate ‘Wavy Navy’, but the deliberate recruitment of civilian expertise for defined naval tasks. In practice, this could be a specialist branch or capability within today’s RNR, consistent with defence’s wider ambition to integrate reservists, regulars, and civilian skills.
This branch could include hydrographic surveyors, geodesists, oceanographers, acoustic data specialists, marine robotics experts, and geospatial analysts. Membership should recognise verified professional competence, while naval rank and authority should reflect military responsibility rather than mirror civilian seniority. A small permanent force would maintain the training pipeline, security clearances, mobilisation roster, and links to operational commands.
Training would combine naval orientation and operational planning with secure information handling, defence data standards, and repeated exercises using representative autonomous survey data. Reservists would need to practise as teams under the naval chain of command rather than exist as a directory of experts assembled after an incident. Employer agreements, liability, availability, and conflicts of interest would have to be settled before a crisis.
In routine service, this proposed reserve could assure nationally important seabed baselines, test change-detection workflows, and scrutinise contractor outputs. During an incident, it could provide rapid survey planning, processing, and uncertainty assessment. In crisis or mobilisation, it could reinforce shore-based intelligence cells and advise commanders on what data can and cannot prove. Not every contributor would require the same service liability; volunteer and sponsored reservists could form a uniformed core supported by pre-cleared civilian specialists. Inherently military decisions would remain under uniformed command.
Societies such as the Hydrographic Society UK and Ireland could help to convene industry and academia, map competence, and develop common exercises. However, these should not command the reserve or become a recruiting agency; their value would lie in providing a neutral professional bridge to a community that defence does not routinely reach.
Conclusion
The Royal Navy already has hydrographic and meteorological specialists, and a reserve as described in this article must augment rather than displace them. Its purpose would be to give the Hybrid Navy sovereign surge capacity and an enduring ability to challenge the outputs of machines and contractors.
Uncrewed vehicles can prolong underwater presence, and commercial partners can provide scale. Reliable AI can accelerate analysis. However, these cannot independently decide whether two datasets are genuinely comparable, which anomaly matters, or what action the evidence justifies. In the sub-threshold contest over the undersea domain, data supplies the evidence, but it is people who turn the evidence into operations.
Liam Flood is a hydrographic survey professional working for Kongsberg Discovery and Honorary Secretary of the Hydrographic Society UK and Ireland. He writes here in a personal capacity.
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A competence held on paper and never exercised is not held, and the gap appears at the moment it is needed, by which time it cannot be rebuilt. Medicines regulation met this when manufacturing and safety monitoring moved to third parties, and its answer was not to keep the capability in-house but to inspect it: a licence holder stays personally answerable for contracted work, tested on a cycle rather than accepted on assertion. A hydrographic reserve buys surge capacity, which is the harder half to build. Whether an oversight function can still challenge what a contractor hands over is a separate question, answered by inspecting the customer.
Could the navy not adopt a model whereby they generate a government-owned force, which is primarily tasked with government work, but can be contracted out to the private market in part, as a way of funding itself and guaranteeing work...? Applicable to a lot of public-private roles in the military, could we not indeed swap the relationship around?