The Royal Navy nuclear-powered attack submarine HMS Anson has docked at HMAS Stirling near Perth, Western Australia, on February 22, 2026, in what officials describe as a historic visit strengthening Indo-Pacific security ties.
This marks the first-ever maintenance activity conducted on a United Kingdom nuclear-powered submarine in Australia, as part of the trilateral AUKUS partnership between Australia, the United Kingdom, and the United States. The Astute-class submarine, crewed by approximately 100 personnel and equipped with torpedoes and land-attack missiles, arrived after a lengthy transit including a stop in Gibraltar, covering over 8,200 nautical miles.
Over the coming month, around 100 personnel from the Royal Navy, UK Submarine Delivery Agency, Royal Australian Navy, ASC Pty Ltd, and Pearl Harbor Naval Shipyard will collaborate on the UK Submarine Maintenance Period (UK SMP). This includes maintenance, familiarisation activities, and training to build Australia’s capabilities in operating and sustaining conventionally armed, nuclear-powered submarines. Two Royal Australian Navy officers are embedded aboard HMS Anson, gaining hands-on operational experience.
The visit aligns with preparations for Submarine Rotational Force–West (SRF-West) at HMAS Stirling, set to begin in 2027, where US and UK nuclear-powered submarines will rotate persistently. It builds on prior milestones, such as visits by US Virginia-class submarines USS Hawaii in 2024 and USS Vermont in 2025, and an earlier Astute-class visit by HMS Astute in 2021 shortly after AUKUS was announced.
Australian Defence Minister Richard Marles highlighted the event as a “historic step” in readiness for Australia’s future submarine fleet, including the upcoming construction of SSN-AUKUS submarines in Adelaide by the end of the decade. UK officials emphasized the commitment to the Indo-Pacific, coinciding with the 125th anniversary of the Royal Australian Navy.
This deployment underscores the deepening military logistics and interoperability in the region amid evolving strategic dynamics, where reliable submarine sustainment far from home ports is essential for extended operations. The successful execution of this first UK SMP outside home waters demonstrates adaptive forward-basing solutions that enhance alliance deterrence and response capabilities in one of the world’s most strategically vital maritime theatres.