Proteus exists because the Royal Navy faces an expanding requirement in the North Atlantic that cannot be addressed through additional ships, personnel or flying hours alone. The area requiring persistent monitoring has grown steadily, while the number of platforms available to deliver that coverage has not.
Undersea activity has increased and subsea infrastructure has taken on strategic importance. Maritime awareness now depends on sustained presence rather than episodic patrols. At the same time, aviation manpower, training capacity and fleet size impose firm limits on how much coverage can be generated using traditional methods.
The UK’s undersea warfare posture relies on RAF-operated maritime patrol aircraft working alongside Royal Navy anti-submarine helicopters. These remain highly capable assets, but availability rather than performance has become the defining constraint. Each sortie consumes finite airframes, crews and maintenance capacity.