SAAB TO DEVELOP LUUV FOR SWEDEN

Saab has secured a contract with the Swedish Defence Materiel Administration (FMV) to develop a Large Uncrewed Underwater Vehicle (LUUV), according to an August 29 press release. The project, valued at $6.3 million (£4.7 million/€5.5 million), marks a significant step in Sweden’s naval defence strategy to becoming a more offensive force. This LUUV initiative aims to produce a new concept for autonomous sub-surface capabilities, with Saab leading the design, construction, and testing.

The LUUV will be a sophisticated sensor platform, serving primarily as a decision support tool for naval operators. The initial phase of the project does not include a weapons payload, focusing instead on key tasks such as monitoring and mapping seabed infrastructure, as well as detecting and deterring threats beneath the surface. This is a direct response to the increasing strategic importance of undersea cables and energy pipelines.

A critical component of the LUUV is the integration of Saab’s advanced autonomous control system, Autonomous Ocean Core. This technology enables vessels to operate autonomously both on and below the water’s surface without direct human intervention. This capability is essential for long-duration missions in complex maritime environments.

Mats Wicksell, Head of Saab’s Kockums business area, highlighted the project’s importance. “It is gratifying that together with FMV and the Swedish Armed Forces, we have the opportunity to work quickly and together to develop a new advanced system in a short time,” he said. He added that the project will create innovative solutions and aligns with Saab’s ongoing work in autonomy.

The development process is already underway, with the first sea trials scheduled for summer 2026. This rapid timeline underscores the urgent need for new underwater security capabilities in the face of evolving threats to critical sub-sea infrastructure. “The biggest change for Sweden is a change in mindset. After 250 years as a non-aligned country, basing our defence on a defensive strategy with some offensive elements, we’re now shifting focus to become an offensive force to establish and maintain control in our area,” Rear Admiral Fredrik Lindén, the Director of the Naval Systems Division at the FMV, is reported to have said in 2024. 

The development of an LUUV would potentially complement Sweden’s existing ISR infrastructure and help to locate potential sources of sabotage or other sub-surface threats as they move through the North Sea. A recent order for the CB90, also from Saab, would further help the country respond to sub-surface threats along its coastline. 

LUUVs: Why are they needed?

The Yantar research vessel is used by the GUGI for its covert operation. Credit: RuMoD

There are two parts to this question. One is quite obvious; Russian submarines are good, they are quiet and can hide effectively in busy sea lanes, making it difficult for NATO forces to track their movements. This is a problem, and one that needs to be resolved for NATO’s security, but it is not entirely novel. The threat that is playing on many minds is Russia’s ability to hold critical national infrastructure at risk, especially undersea cables. “Targeting critical infrastructure is likely to be an important part of Russia’s approach to coercion at sea,” Dr Sidharth Kaushal, the Sea Power fellow at RUSI, told Calibre Defence recently. 

He emphasised that Russia has a range of assets and means that could be used to damage deep-sea infrastructure, as evidenced by the many incidents of boats dragging anchors across cables and pipelines in the North Sea. But one element of concern is the Main Directorate of Deep Sea Research (GUGI) , a body independent of the Russian Navy that answers directly to the Russian MoD. 

“GUGI operates a range of deep-diving submarines, such as the titanium-hulled Losharik, Paltus and X-Ray, which are capable of operating at extreme depths, where the impact of sabotage would be particularly difficult to repair. It also operates vessels such as the Belgorod (a stretched Oscar-class submarine, which acts as a mothership for vessels like the Losharik) and surface vessels such as the Yantar, which can act as operational hubs for  deep-diving, remotely-operated vehicles like the Harpsichord,” he explained. 

In a nutshell, the GUGI appears to be set up to build intelligence of deep sea critical infrastructure as well as to damage it in peacetime, during a crisis, or conflict. Tracking the movements of its capabilities underwater and on it is logically a critical requirement. This is reflected in projects like Sweden’s LUUV, but potentially also Denmark’s SkyGuardian procurement, and Norway’s Type 26 programme.

Calibre comment

There are a range of nations concerned with these threats and developing their own solutions. The UK introduced the Excalibur Extra-Large Uncrewed Underwater Vessel into service in May this year, which is set to help the Royal Navy understand how best to use the platforms. BAE Systems developed the Herne XLUUV, presumably for the same requirement, but also with a focus on sub-surface ISR. Defence tech companies like Helsing and Anduril have also developed solutions that are designed to provide a sustained ISR capability on the seabed, in the hope that threats can be mapped and detected. Logically, improving the ability to detect and track threats posed by the GUGI, should also carry-over to the ability to track Russia’s more conventional submarine capabilities. 

By Sam Cranny-Evans, published on September 9, 2025. Credit for the lead image is Saab.