Russian incursions into UK waters have increased by a third in just two years, the head of the Royal Navy has revealed.

The Kremlin is also spending vast sums on a submarine programme intended to dominate the North Atlantic and the Arctic, according to the First Sea Lord.

Today, General Sir Gwyn Jenkins gave his most alarming assessment yet of the maritime threat to Britain and the race against time to guard against the Kremlin.

There are also fears the UK could be specifically targeted due to its fragmented relationship with both the United States and European allies.

Addressing the Royal United Services Institute this morning Sir Gwyn also announced ambitious deadlines for a ‘Hybrid Navy’.

Patrols of the North Atlantic to monitor hostile activities by uncrewed systems will start this year, jet powered drones will operate from the UK’s aircraft carriers by next year and uncrewed escort ships with patrol alongside conventional warships by the year after that.

Sir Gwyn also revealed how the Royal Marines have received their first batch of 20 high-speed K3 Uncrewed Surface Vessels to be used for security roles.

The dramatic increase in Russian threats to British waters has stunned naval chiefs into action.

Lessons are also being learned from Ukraine’s drone ship successes in the Black Sea and the Iran conflict.

The exact numbers remains highly classified but Sir Gwyn said: ‘We have seen Russian incursions into our waters increase by almost a third in the last two years. In 2025 alone the Royal Navy was required to respond dozens of times, pitting homeland defence against Russian Navy vessels.

‘It is Russia’s investment in its submarine programme that poses the most acute threat. Our submarines are spending a substantial amount of time responding to Russia subsurface activities.

‘Therefore the Hybrid Navy will be geared towards the North Atlantic and the High North, fundamentally the priorities of our geography. We have global responsibilities but this is where our long term focus must remain and where Russian surface and subsurface activities continue to pose a persistent challenge.

‘The Hybrid Navy is a vision for a fleet transformed. Warships will not be able to survive without uncrewed support. Those technologies are advancing at a speed that would have seemed inconceivable even a few years ago.’

In his first major speech since US President Donald Trump and Secretary of War Pete Hegseth mocked the Royal Navy, Sir Gwyn defended its personnel and suggested the conflict in the Gulf had revealed the vulnerability of traditional naval platforms.

He said the service’s warfighting readiness plan was a blueprint to ensure Britain can fight and win.

Sir Gwyn continued: ‘Recent developments have put the Royal Navy in the spotlight. Were we prepared enough? Were we prepare to fight and if so what with. I am not here to dodge those questions. I am here to show that we have a plan. The Royal Navy is rising to the challenge in front of us.

‘Warfare is evolving rapidly. We must end the mentality that we need ever more expensive and ever larger platforms. Our first Hybrid Navy wargame proved substantial increase in combat mass and tactical choices, capability increased threefold. Readiness to respond improved.’

In the future partnerships with regional naval allies are expected to deepen, including Norwegian sailors crewing Royal Navy ships, Norway, Canada and other navies purchasing the same ships used by the UK and the signing of a joint declaration of intent to defend the Northern Atlantic.

Privately, senior officers’ fears are increasing that the UK will be drawn into direct conflict with Russia. Today, they described an ‘open border’ with Russia through the North Atlantic, the ‘illusion of Britain’s safety’ and how our allies are doubting our political will.

Britain may also be more vulnerable due to the fracturing of its relationship with the United States and difficulties with European countries following Brexit. They conceded their views have darkened in recent years, including that belonging to NATO is no longer the guarantee of protection it once was.

Senior officers fear the United States would not be in a position materially to come to the aid of Britain should Russia launch a naval war, were it to be engaged in a conflict in the Pacific at the same time.

After studying the Iran conflict they doubt the US would be able to participate in two conflicts simultaneously.