The US Navy’s (USN’s) submarine service is continuing to take key steps in developing and deploying uncrewed underwater vehicle (UUV) capability through exercises and operations, Vice Admiral Rob Gaucher – the USN’s Commander, Submarine Forces (COMSUBFOR) – told the Combined Naval Event 2025 (CNE 25) conference in Farnborough, UK in mid-May.
These steps are following the pathway towards delivering a permanently deployed capability, Vice Adm Gaucher explained. “Our intention is now to … maintain our UUVs deployed around the world on at least one submarine, somewhere in the world, 24 hours a day, seven days a week, 365 days a year,” he said. “We’re on a path to do that.”
The first step Vice Adm Gaucher discussed was the operational deployment of a torpedo tube launched-and-recovered (TTL&R) autonomous underwater vehicle (AUV), onboard the Virginia-class nuclear-powered attack submarine (SSN) USS Delaware.
At CNE 24, Vice Adm Gaucher had announced that the USN was ready to deploy a TTL&R UUV capability onboard an operational submarine for the first time, with deployment set to commence onboard Delaware by the end of 2024 in the European theatre of operations. At CNE 25, Vice Adm Gaucher confirmed “Delaware is deployed today with that capability.”
The capability is the HII Yellow Moray (REMUS 600) UUV. Development of the TTL&R capability since 2024 included testing in US waters and then, once in the European theatre, in waters off Norway and the UK. A ‘fail fast, learn fast’ mindset has been adopted, Vice Adm Gaucher told the CNE 25 conference. In trials off the US, challenges in recovering the UUV onboard for operators learning a new craft were addressed through re-writing procedures and re-designing the user/UUV interface for what is a complex system.
In further trials in a Norwegian fjord, recovery onboard Delaware was achieved after several tries; however, in a second deployment, recovery onboard the submarine could not be completed, so a surface ship was used instead. Following work conducted on the UUV back in the US, when it was returned to the boat in Norway, the UUV could not be loaded using a crane, so divers had to work out how to embark it onboard via a torpedo tube. This was the first time this had been done, and it was done successfully, Vice Adm Gaucher explained.
Delaware then deployed to the British Underwater Test and Evaluation Centre (BUTEC) range, off northwest UK. Three successful UUV sorties were conducted in two phases, with the vehicle deploying for between six and 10 hours, returning to the boat, and driving back into the tube. “That was a big success, but it’s really been a journey,” said Vice Adm Gaucher. “We have got to get those vehicles out in the water and learn those lessons fast.”
Another Virginia SSN has also used the BUTEC range for testing UUV capability, in seabed warfare tasking, Vice Adm Gaucher explained. A UUV was deployed from USS New Mexico’s lockout trunk and, with special forces divers operating it remotely, the vehicle delivered an effector down to the seabed.
While the challenges in developing the capability to deploy UUVs from submarines including to conduct seabed activities have been robust, Vice Adm Gaucher said the submarine service had come together over the last year to develop good plans and to deliver them. “We went out and did it,” he added.
“Our intention is to repeat those deployments and, in about a year, deploy a TTL&R remotely operated vehicle [ROV] with that same capability, so we can defend our critical undersea infrastructure (CUI),” Vice Adm Gaucher continued.
Alongside the technical challenges in deploying UUVs from boats, the submarine force is also tackling the challenge of building operator confidence in the capability. It is doing this through what is called the ‘UUV confidence course’.
As a core part of this course, Vice Adm Gaucher said the navy has built an ‘underwater city’, drawing on automotive industry developments with self-driving cars that have included (for example) building mock-up cities for the vehicles to navigate around. Using various UUV types, more than 70 ‘runs’ have been conducted around the ‘underwater city’. Navigation plans are devised for a UUV and then executed, with execution then compared to the original plan to understand where improvements are needed and to thus help build confidence in the vehicles, capabilities, procedures, and tactics. The aim here, said Vice Adm Gaucher, is “to wring out all the problems in advance so that we’re not learning once we go into execution: if we’re not going to have a person in the loop, we need to have that confidence built”.
A next step here is conducting the ‘UUV confidence course’ at NATO’s ‘Dynamic Messenger’ maritime uncrewed system (MUS) operational experimentation (OPEX) exercise, taking place off Troia, southern Portugal in September in tandem with the Portuguese Navy/NATO co-hosted ‘REPMUS’ (‘Robotic Experimentation and Prototyping augmented by Maritime Unmanned Systems’) exercise. With the course for this exercise to be known as an ‘expeditionary confidence course’, the ‘underwater city’ will be set up off Troia, with participating NATO navies invited to bring their UUVs. Part of the OPEX and analysis process will include sharing ‘run’ data via Starlink with USN operators back in the US, who will use artificial intelligence to generate an assessment of ‘run’ effectiveness.
Vice Adm Gaucher explained that the USN can already do this with its UUVs, and hopes to be able to do it with NATO partner UUVs at ‘Dynamic Messenger’. Noting that sending NATO partner UUV data back to USN operators in the US is a ‘stretch goal’, a more local solution could be sourced instead, he added. Nonetheless, the admiral stressed, “[The ‘stretch goal’] is our target …. That’s my ‘put the pedal to the metal’ with UUVs to push forward on our capabilities there.”
Its high-level involvement in a high-profile MUS OPEX activity like ‘REPMUS’/‘Dynamic Messenger’ underlines the importance for the USN Submarine Force of rapidly accelerating operational use of UUV capability. “Commander, Submarine Force’s/Allied Submarine Command’s commitment to ‘Dynamic Messenger’ highlights the shared imperative for the US and all our NATO partners to defend the seabed,” Vice Adm Gaucher told Naval News. “By demonstrating interoperability between our platforms, people, and robotic autonomous systems, we build the capability and capacity to deter those who might threaten our CUI.”
