HMS Anson arrived in Western Australia today to undertake the first-ever maintenance activity on a Royal Navy nuclear-powered submarine in Australia. The visit marks a significant milestone in AUKUS preparations and Australia’s ambition to operate conventionally armed, nuclear-powered submarines.
Anson sailed from Gibraltar on 23 January and completed the 8,200 nautical mile non-stop transit over the course of a month at sea before entering HMAS Stirling. Her entry to the base was slightly delayed by infrastructure set up for the annual Rottnest Channel Swim preventing transit through the channel, although the swim was eventually cancelled due to bad weather.
Anson’s direct passage to Australia dispels speculation that she might be diverted for Tomahawk land-attack operations in the Middle East. Political signals from London, including the Prime Minister’s refusal to authorise the use of UK airbases for US strikes on Iran, underline the government’s choice to avoid action in the region.
To many observers, the timing of the deployment to Australia appears extraordinary. With no other RN attack submarines available and a weakening surface fleet, while tensions with Russia continue to rise, sending the sole operational SSN to the other side of the globe invites scrutiny. The UK must honour its commitments under AUKUS, but in the near term, there is a legitimate debate about whether more immediate regional concerns should take precedence.
Positioning Britain’s only available attack submarine so far from home waters risks appearing inconsistent with firm official messaging that any hostile act by Moscow will be met with strength and resolve. The small SSN force represents the UK’s most potent conventional deterrent and most powerful asset to deter malign Russian underwater activity.
Over the coming weeks, around 100 personnel will work on the boat in a Submarine Maintenance Period (SMP). The effort brings together the RN, the UK Submarine Delivery Agency (SDA), the Royal Australian Navy (RAN), ASC Pty Ltd and specialists from Pearl Harbour Naval Shipyard. The activity represents the first time the UK has conducted such a maintenance period for one of its nuclear-powered attack submarines outside home waters.
This work builds directly on Australia’s recent experience supporting USN Virginia-class boats, including USS Hawaii in 2024 and USS Vermont in 2025. Each step incrementally develops the industrial skills, regulatory systems and supply chains necessary to sustain nuclear-powered submarines safely and routinely. HMS Astute previously visited Australia in 2021, shortly after the AUKUS pact was agreed.
HMAS Stirling will be the base for Submarine Rotational Force-West (SRF-West), under which US and UK nuclear-powered submarines will rotate through Western Australia on a persistent basis. Establishing the workforce, facilities and nuclear stewardship arrangements to support this presence is central to the credibility of AUKUS Pillar I.
Two RAN officers are currently embedded aboard HMS Anson, gaining first-hand operational experience in a conventionally armed, nuclear-powered submarine. More than 50 Australians are now embedded across the UK Defence Nuclear Enterprise, while the RN has delivered offshore nuclear safety training to over 950 personnel associated with the Australian Submarine Agency.
These exchanges illustrate that AUKUS is as much about people as platforms. Developing a cadre of experienced nuclear-qualified engineers, maintainers and operators will take years. Anson’s maintenance period accelerates this learning curve, exposing Australian personnel to the standards and procedures that underpin safe submarine operations.
During the visit, AUKUS partners are expected to conduct combined Pillar I and Pillar II activities, including testing the interoperability of the C2 Roboticts Speartooth Large Uncrewed Underwater Vehicle (LUUV) with HMS Anson. In parallel, ASW artificial intelligence algorithms associated with AUKUS Pillar II will be assessed and refined using data from the Royal Australian Air Force P-8A Poseidon maritime patrol aircraft.
