The submarine, which began its mission in late August last year, was welcomed back on 17 March by Prime Minister Sir Keir Starmer and Defence Secretary John Healey during a visit to Gare Loch. It marked the first visit by a British Prime Minister to a Royal Navy submarine in over a decade.
HMS Vanguard is the lead boat of the four Vanguard-class submarines, which serve as the UK’s sea-based nuclear deterrent. These submarines have been on continuous patrol since 1969 as part of Operation Relentless, ensuring that at least one vessel is always at sea, armed with up to 16 Trident II D5 ballistic missiles.
The unprecedented duration of the patrol has raised questions among defence analysts regarding provisions and logistics. Vanguard-class submarines typically carry food supplies sufficient for three to four months, prompting speculation about undisclosed resupply methods or surfacing, which would contradict long-standing stealth protocols.
Each of the last eight Vanguard-class patrols has exceeded five months, highlighting a pattern of extended deployments. The Ministry of Defence has not commented on the logistics, maintaining the need for operational secrecy.
HMS Vanguard features a displacement of 15,900 tonnes, a nuclear reactor with a 30-year lifespan, and advanced sonar and missile systems. In addition to Trident missiles, the submarine is armed with Spearfish torpedoes and operates with a crew of 135, divided into two alternating teams for continuous readiness.
Before HMS Vanguard returned to base, another Vanguard-class submarine departed Faslane on 12 March to maintain uninterrupted deterrence operations. The Vanguard-class is expected to be gradually replaced by the new Dreadnought-class submarines from the early 2030s.
