The Royal Navy’s newest nuclear-powered attack submarine has arrived at its new home on the Clyde after completing its first dive at sea off the west coast of Scotland.
HMS Agamemnon, the sixth of the Royal Navy’s Astute-class hunter-killer submarines, arrived at HM Naval Base Clyde at Faslane on Friday (2 October).
The 97-metre-long submarine sailed from the BAE Systems shipyard in Barrow-in-Furness on 25 September and has since been undergoing its first sea trials with a crew of around 100 submariners.
Its journey to Scotland included Agamemnon’s first dive at sea, carried out in the Inner Hebrides Exercise Areas while being monitored by a Royal Navy Merlin helicopter.
The arrival marks another step towards the £1bn-plus submarine entering operational service with the Royal Navy.
Members of the Submarine Flotilla lined up at Faslane to welcome the vessel alongside senior officers including Director Submarines Rear Admiral Andy Perks, Naval Base Commander Clyde Commodore Andy Bray and Commander of the Submarine Flotilla Commodore Ben Haskins.
“The arrival of HMS Agamemnon at HM Naval Base Clyde is a significant milestone for the Royal Navy,” said Rear Admiral Perks.
“Her delivery reflects the dedication, skill and collaboration of thousands of people across our Defence Nuclear Enterprise, who have worked together to build one of the world’s most capable attack submarines and deliver a formidable warfighting capability for the United Kingdom.
“As she begins a demanding programme of sea trials and operational preparation, I am delighted to welcome the Submarine and her Ship’s Company to their new home on the Clyde, and I look forward to seeing them join the operational fleet in due course.”
Agamemnon is one of the largest and most advanced attack submarines ever operated by the Royal Navy.
The Astute-class vessels are 97 metres long, displace around 7,400 tonnes and are powered by nuclear reactors, meaning they do not need to refuel during their operational lives.
Unlike Britain’s Vanguard-class submarines, which carry the UK’s nuclear deterrent, Agamemnon is conventionally armed.
Its weapons include Spearfish heavyweight torpedoes and Tomahawk land-attack cruise missiles capable of striking targets more than 1,000 miles away.
The submarines are designed for missions including anti-submarine warfare, surveillance and intelligence gathering, protecting Royal Navy task groups and supporting UK, NATO and allied operations.
They are also capable of travelling around the world while remaining submerged, producing their own oxygen and drinking water while at sea.
The Astute class does not use traditional optical periscopes, instead relying on high-specification video systems to scan the surface.
The Commanding Officer of HMS Agamemnon, Commander John Gabb, said: “It is an enormous privilege to be the first person to command this vessel at sea.
“We will get to know Agamemnon well over the coming months, but this submarine is incredibly quiet, has a world-class Sonar and will be home to us all as we generate for operations.”
Agamemnon’s arrival on the Clyde comes after more than a decade of construction.
Its keel was laid in July 2013 before the submarine was officially named in April 2024 and launched later that year.
King Charles III formally commissioned HMS Agamemnon during a ceremony at Barrow on 22 September 2025.
The vessel carried out its first controlled dive in October last year inside BAE Systems’ Devonshire Dock Hall, where it was submerged to a depth of around 15 metres as engineers tested its stability and systems.
Its first dive in open water took place during the journey north to Faslane.
The submarine’s performance, speed, manoeuvrability and seaworthiness will now continue to be tested over the coming weeks and months before it is cleared for frontline operations.
Commodore Ben Haskins, said: “Welcoming HMS Agamemnon, the newest submarine of the Flotilla into her new home at HM Naval Base Clyde is a special moment for our Service. To get here the crew have conducted themselves with the professionalism and dedication that is expected from every one of our submariners.
“Today’s milestone marks the first step on a journey which will soon see this outstanding boat delivering high-tempo operations across the globe.”
The submarine joins HMS Astute, HMS Ambush, HMS Artful, HMS Audacious and HMS Anson in the Astute programme.
All of the Royal Navy’s submarines are now based at HM Naval Base Clyde, which has become the home of the UK’s Submarine Service.
A seventh and final Astute-class submarine, HMS Achilles, remains under construction at Barrow.
Agamemnon’s arrival also coincided with an anniversary for the UK’s submarine fleet, taking place exactly 125 years after the Royal Navy’s first submarine, Holland 1, was launched.