With British industrial support, the Royal Navy has taken a significant step in the development of autonomous submarines: the prototype submarine XV "Excalibur" operating off Plymouth was controlled from a command centre 16,000 kilometres away in Australia. As an Extra-Large Unmanned Underwater Vehicle (XLUUV), "Excalibur" is still just an unarmed demonstrator from the British company MSubs, whose integration into military operations such as underwater reconnaissance and anti-submarine defence is to be tested. At almost 12 metres long and weighing 19 tonnes, it is reminiscent of the smallest submarines of the Second World War. Without a crew, XLUUVs offer plenty of space for sensors and weapons payloads - depending on the required mission profile. No information is yet available on the propulsion system. The tests carried out in connection with the international Talisman Sabre manoeuvre (19 nations) open up completely new opportunities for cooperation within the framework of the AUKUS agreement between Australia, the UK and the USA.