German defence technology company FLANQ and submarine systems supplier Gabler have completed the surface part of the sea acceptance test (SAT) for Ranger, an unmanned surface vehicle (USV) designed to be deployed from a submarine's torpedo tube.
The Ranger demonstrator is a torpedo tube-launched USV (TTL USV) intended for intelligence, surveillance and reconnaissance (ISR). A standard 21-inch (530mm) submarine torpedo tube can be used to launch the vessel, which is designed to rise to the surface on its own and then carry out covert ISR missions.
The test was conducted in June and announced by the two companies in July. They said the SAT confirmed the vessel was seaworthy and that its key technologies were integrated and operating. Performance data were also collected and checked throughout the trials.
The test's completion also brought the programme's proof-of-concept phase to a close.
The vessel is 4.5 metres (15 feet) long. Its hull dimensions are dictated by the launch interface, and the hull has been described as tubular with a diameter of just under 21 inches.
Ranger has a folding keel for stability and a folding mast to elevate its sensors on the surface. Both are stowed for transit through the torpedo tube and are fully deployed after the vessel surfaces. Propulsion is provided by an electric drivetrain.
When Gabler unveiled the concept in 2025, it gave the hull a depth rating of 300 metres (980 feet). The figure reflects the requirement for the vessel to withstand submergence at the carrier submarine's operating depth before it is released.
Mission equipment is carried in a configurable payload bay. At the time of the concept's unveiling, Gabler said Ranger's sensors will be able to provide real-time surveillance and reconnaissance to naval forces facing contested conditions.
The USV is intended to be reusable. Gabler said that submarines can deploy the craft and retrieve it discreetly without putting themselves at risk. FLANQ added that the USV can also be recovered by surface assets.
FLANQ is responsible for autonomy. The company described its proprietary autonomy stack as combining data fusion and edge computing, in addition to being vehicle- and sensor-agnostic. As with other systems developed by FLANQ, the USV utilises a number of commercial-off-the-shelf components.
Ranger shares its hull with a strike variant of the USV intended for single-use tactical missions. The variant is referred to as Strike and has been described as a one-way-attack vessel.
The TTL USV programme began with a strategic partnership announced on August 20, 2025.
Under the arrangement, FLANQ handled payload integration as well as design and manufacturing, while Gabler, whose products include submarine masts, components for vessels and tactical gateways, handled system integration.
The two companies said development is continuing with the aim of providing operational capability to end users. Gabler is responsible for commercialising the programme, supplying naval customers and integrating the system with host platforms.
The partners have identified NATO and European naval forces as the target market for both the Ranger and Strike variants.
| Ranger | |
|---|---|
| SPECIFICATIONS | |
| Type of vessel: | USV – Surveillance |
| Designer: | FLANQ, Germany |
| Builder: | FLANQ, Germany |
| Length overall: | 4.5 metres (15 feet) |
| Electronics supplied by: | Gabler |