IN Brief:
- Australian and US personnel tested AUKUS Pillar II subsea capabilities during RIMPAC 26.
- HUGIN, Schilling, Lightfish Seasat, and Rock Lobster systems were operated across autonomous, remotely controlled, and communications roles.
- The work is concentrating increasingly on interoperability between allied systems rather than isolated vehicle performance.
Australia and the United States have tested a group of autonomous, remotely operated, and communications systems during RIMPAC 26, using an AUKUS Pillar II activity to examine how separate undersea capabilities can operate together around the protection of critical seabed infrastructure. Australian and US personnel worked with vehicles and communications equipment across a series of subsea and seabed warfare scenarios rather than evaluating a single platform in isolation.
The Australian Department of Defence deployed systems from Australian Defence Vessel Guidance, which supports robotic, autonomous, crewed, and uncrewed underwater systems and undersea surveillance work. Personnel from the Royal Australian Navy, Defence Science and Technology Group, and United States Navy took part in the activity.
Australia’s equipment included a Kongsberg HUGIN Superior autonomous underwater vehicle working alongside a Schilling work-class remotely operated vehicle. The two systems conducted navigation and search activity within the exercise area, bringing together platforms designed for different parts of the undersea mission. An autonomous vehicle can cover an area with limited direct intervention, while an ROV provides controlled observation or intervention where closer inspection is required.
The partners also deployed Australia’s Lightfish Seasat uncrewed surface vessel and Rock Lobster deployable underwater acoustic communications relay. Rock Lobster was developed by L3Harris with the Royal Australian Navy and Defence Science and Technology Group, and the exercise included interoperability work between Australian and American underwater acoustic communications technologies.
That communications layer is central to the wider AUKUS effort. Underwater vehicles have developed rapidly in endurance, navigation, payload capacity, and autonomy, but combining assets from different national inventories requires more than compatible mission descriptions. Vehicles, surface relays, operators, and command systems have to exchange useful information in an environment where conventional radio communications and continuous satellite navigation cannot be assumed beneath the surface.
The RIMPAC activity therefore concentrated on the interfaces between systems as much as the platforms themselves. Acoustic links, mission planning, data formats, command arrangements, and the ability to retask equipment become part of the capability once several autonomous and remotely operated assets are expected to contribute to the same mission. A high-performance vehicle that requires a bespoke integration effort whenever it works with an allied force places a different burden on operators from one built around repeatable interfaces.
Critical undersea infrastructure provided the mission setting for the latest activity. Subsea cables, pipelines, and other seabed assets create demanding surveillance problems because areas can be geographically extensive and faults or suspicious objects may require progressively closer investigation. Combining long-range autonomous search with remotely operated inspection and surface or underwater communications offers one way to divide those tasks across different equipment.
The trial builds on the Maritime Big Play exercise and experimentation series, which has been used to develop AUKUS interoperability between uncrewed maritime capabilities. Repeated experimentation gives acquisition and engineering teams an opportunity to expose integration problems before larger procurement decisions fix interfaces, software baselines, and support arrangements into service.
For suppliers, this places increasing weight on system compatibility alongside headline specifications such as endurance, operating depth, sensor resolution, or speed. Kongsberg, L3Harris, and other companies involved in the systems being tested are operating in programmes where their equipment may have to contribute data to allied networks and work alongside products designed to different national requirements.
There is still a substantial gap between an exercise and a fielded multinational architecture. The Australian announcement does not identify a procurement quantity, programme value, common technical standard, or timetable for wider deployment. Nor does the RIMPAC activity establish that every system tested will become part of a permanent AUKUS equipment set.
It does show where Pillar II experimentation is becoming more demanding. Rather than demonstrating that an autonomous vehicle can navigate or that an acoustic relay can pass a message, Australia and the United States are putting several technologies into the same mission environment and testing where the connections work and where they need improvement.
The next useful measure will be repeatability. If future exercises can use common interfaces, reduce integration work, and bring additional allied systems into the same architecture without rebuilding the network each time, the experimentation will begin to resemble an acquisition framework. Until then, RIMPAC 26 provides another practical test of whether AUKUS undersea autonomy can function as a connected force rather than a collection of capable machines.
