AUKUS Maritime Big Play Pacific Underway Off San Diego With 40+ Uncrewed Technologies

The AUKUS partners are in the closing phase of Maritime Big Play Pacific, a large trilateral demonstration off Southern California in which Australia, the United Kingdom and the United States are testing how crewed warships and uncrewed systems can operate as a single force. The UK Ministry of Defence highlighted the event on its official X account on 19 October 2026, saying Maritime Big Play is underway in San Diego and will show how the three nations can integrate, coordinate and fight together across the whole maritime domain.

What Maritime Big Play Pacific is testing

According to U.S. Navy information, the demonstration is hosted by the Naval Information Warfare Center (NIWC) Pacific, U.S. Pacific Fleet and the U.S. Marine Corps, and sponsored by the Office of the Under Secretary of War for Research and Engineering’s Critical Technologies directorate. More than 40 technologies drawn from the three nations’ defence industrial bases are being put through operational vignettes that include live fire.

The stated goals are to develop common command-and-control solutions that can generate combat mass, to provide secure communications “from stratosphere to seabed”, and to integrate autonomous systems with conventional fleets and allied forces. The Navy has not publicly listed every system taking part or the number of vessels involved.

Part of AUKUS Pillar II

The event falls under AUKUS Pillar II, the strand of the partnership focused on advanced capabilities such as autonomy, artificial intelligence, electronic warfare and hypersonics, separate from the Pillar I nuclear-powered submarine programme. It builds on three years of trilateral trials of shared command-and-control and secure communications. Gerry Tighe, the U.S. lead for the exercise, has described it as a significant step towards partners integrating and fighting together, and said it removes technical barriers to bringing systems from different industrial bases into operations.

Australia adds new undersea payloads

The exercise coincides with an Australian announcement on 19 October on new payloads for the Ghost Shark and Speartooth uncrewed underwater vehicles and the Bluebottle uncrewed surface vessel. Canberra cited roles such as remotely delivering supply caches, sea mines and small uncrewed aircraft, for missions including sea denial and protection of undersea infrastructure. Some of these payloads are taking part in Maritime Big Play Pacific.

Deputy Prime Minister and Defence Minister Richard Marles and Defence Industry Minister Pat Conroy linked the work to planned investment of up to A$5.8 billion over the decade in autonomous and uncrewed undersea warfare, including A$1.7 billion for a fleet of Australian-built Ghost Shark vehicles for the Royal Australian Navy.

Featured image: Royal Navy sailors operate an ROV during an earlier AUKUS Pillar II event (December 2024). U.S. Navy photo by Petty Officer 1st Class Justin Yarborough / Public domain, via Wikimedia Commons