At DSEI 2025 in London, Leidos unveiled its new Sea Dagger platform—an innovative multirole surface craft designed to meet the UK Ministry of Defence’s (MoD) Commando Insertion Craft (CIC) requirement. Developed in collaboration with VARD Marine and L3Harris Technologies, Sea Dagger is positioned as a modular solution for Royal Marines’ future amphibious and littoral strike operations under the UK’s Future Commando Force (FCF) modernization effort.
Sea Dagger Concept Targets Future Commando Force Needs
The Sea Dagger is Leidos’ response to the UK MoD’s CIC program—a procurement initiative intended to replace aging landing craft with a new generation of fast, stealthy insertion platforms optimized for covert operations in contested littorals. The CIC program is part of the broader Royal Navy transformation strategy that includes Project Selborne and Littoral Response Groups (LRGs).
Key design drivers for the CIC include:
- Low radar cross-section and infrared signature
- High-speed transit capability (targeting >35 knots)
- Shallow draft for beach access and riverine ops
- Modular payloads including ISR sensors or weapon stations
- Capacity to insert a section-sized force (~12–16 troops)
The Sea Dagger aims to address these requirements through a trimaran hull form optimized for stability at speed and modularity. According to Leidos representatives at DSEI, the platform can be configured for troop insertion, ISR missions, or command-and-control roles depending on mission profile.
Design Features: Trimaran Hull and Modular Mission Bay
The Sea Dagger employs a trimaran hull configuration—unusual in this class—which provides enhanced stability during high-speed maneuvers and greater internal volume compared to monohulls. This allows for more flexible mission payloads while maintaining a compact footprint suitable for launch from amphibious motherships or transport ships.
Key technical features include:
- Length: Approximately 18–20 meters (configurable)
- Speed: Over 35 knots with waterjets
- Crew: Minimal crew (2–3), plus up to 16 embarked troops
- Sensors: Optional EO/IR turret; radar; secure comms suite
- Modularity: Swappable mission modules via central bay
The vessel can be outfitted with remotely operated weapon stations (ROWS), unmanned surface or aerial vehicles (USVs/UAVs), or additional fuel tanks depending on operational range requirements. The open architecture approach also facilitates future upgrades in autonomy or electronic warfare systems.
A Collaborative Industry Approach: Leidos, VARD Marine & L3Harris
The Sea Dagger is being developed through a tri-party collaboration between Leidos (prime contractor), VARD Marine (naval architecture), and L3Harris Technologies (mission systems integration). Each partner brings domain-specific expertise aimed at accelerating prototyping while aligning with MoD procurement pathways such as Spiral Development or Rapid Capability Office initiatives.
- Leidos: Systems integrator; overall program lead; C4ISR integration experience from US DoD programs like ACTUV/Sea Hunter.
- VARD Marine: Responsible for hull design; known for offshore patrol vessels and Arctic-capable designs.
- L3Harris: Providing communications suite, sensor integration, and potential remote weapons interface.
This collaborative model reflects broader trends in naval acquisition where modularity and open systems architectures are prioritized over bespoke legacy platforms. It also aligns with NATO interoperability goals via STANAG-compliant interfaces.
CIC Program Context: Timelines and Competitors
The UK’s CIC requirement was formally outlined in late 2021 as part of efforts to reconfigure Royal Marines into a more agile expeditionary force capable of operating from forward-deployed Littoral Response Groups (North/Med). The MoD seeks an initial operational capability by ~2027–2028 with full-rate production potentially extending into the early 2030s.
The CIC competition has drawn interest from multiple vendors. Known contenders include:
- BMT Caimen-90E: A stealthy high-speed monohull design derived from BMT’s proven landing craft lineage.
- Damen Fast Landing Craft family: Offers scalability across sizes; already fielded by several NATO navies.
- MST Group’s SPMT series: A British-designed multi-role platform tailored for special forces use.
- Austal’s Sentinel-class derivatives: Leveraging Australian experience in aluminum-hulled fast craft construction.
- Lurssen’s Special Forces Boat concepts: Emphasizing low observability and rapid deployment features.
No downselect has yet been announced by DE&S (Defence Equipment & Support), but industry sources suggest that prototype trials could begin as early as mid-2026 under Project CHARIOT—a parallel testbed initiative supporting FCF mobility solutions.
Littoral Strike Implications and Export Potential
If selected by the MoD, Sea Dagger would become a key enabler of distributed littoral operations under the Future Commando Force construct—supporting stealthy insertions from sea bases such as RFA Lyme Bay or future Multi-Role Support Ships (MRSS).
The platform may also appeal to allied nations pursuing similar capabilities amid growing emphasis on Indo-Pacific grey zone deterrence. Potential export customers could include Norway’s Coastal Ranger Commandos or Australia’s Army Littoral Manoeuvre Group given shared doctrinal shifts toward amphibious raiding supported by small combatant craft fleets.
An optionally unmanned variant may also be explored under NATO DIANA frameworks focused on autonomous maritime ISR platforms—especially if paired with AI-enabled navigation suites already under development within Leidos’ maritime autonomy portfolio.
Sustainment Strategy and Integration Pathways
Sustainment considerations are built into Sea Dagger’s design philosophy via commercial off-the-shelf components where feasible—reducing lifecycle costs compared to bespoke SOF platforms like Sweden’s CB90HSM or US SOCOM’s Combatant Craft Medium Mark I/II series. The use of containerized maintenance kits further supports forward-deployed logistics models envisioned under LRG deployments in austere theaters like West Africa or Southeast Asia.
If adopted by the Royal Navy/Royal Marines, integration pathways could include compatibility with existing davit systems aboard Bay-class LSD(A)s as well as future MRSS designs currently being scoped by Team Resolute consortium members including Harland & Wolff. Interoperability testing with NATO partners may also occur during BALTOPS or Joint Warrior exercises post-IOC declaration (~2028).
Sourcing & Outlook
The unveiling of Sea Dagger underscores how rapidly evolving special operations requirements are reshaping naval procurement priorities across NATO allies. As threats shift toward contested littorals—from Black Sea flashpoints to South China Sea grey zone standoff—the demand signal is clear: smaller, faster, smarter insertion platforms are no longer niche—they’re foundational assets in modern amphibious warfare doctrine.
