New Year, New Gear: Threats, Modularity, and Agility to Drive Subsea Defense in 2026
The year 2025 will be remembered as one of accelerating technological evolution and mounting geopolitical strain in the maritime domain. As the curtain rises on 2026, the stage is set for further disruption driven by advanced technologies, evolving undersea threats, and contested maritime spaces. From the North Atlantic to the Persian Gulf, from seabed imaging to surface surveillance, marine technology is increasingly central to securing access, protecting infrastructure, and managing escalation at sea. While the precise trajectory of these developments remains uncertain, six areas are likely to shape subsea defense in the year ahead.Port and Harbor SecurityOn December 15, 2025, Russia’s Novorossiysk Naval Base was rocked by a powerful underwater explosion. The Ukrainian Security Service (SBU) subsequently claimed to have struck a Russian Kilo-class submarine berthed inside the harbor using a previously unrevealed UUV, "Sub Sea Baby." If accurate, the incident marked the first known use of a UUV to conduct an attack inside a defended naval port. Beyond its impact on Russia’s Black Sea Fleet, the strike exposed the vulnerability of well-protected, high-value harbors to uncrewed systems, and highlighted the ongoing convergence of mines, torpedoes, and UUVs. As a result, 2026 may see heightened interest in port and harbor security, including underwater barriers, intrusion detection systems, and non-kinetic counter-UUV systems, such as the Stingray net system from Annapolis-based Oceanetics.Critical Underwater Infrastructure DefenseRecent subsea incidents continue to underscore the vulnerability of critical underwater infrastructure (CUI) and the growing need for systematic protection. Repeated disruptions to submarine cables and pipelines in the Baltic Sea, South China Sea, and Red Sea have exposed how contested the seabed has become. In response, NATO announced Operation Baltic Sentry in January, 2025 to enhance vigilance and deterrence in the Baltic Sea. Similarly, in December 2025 the United Kingdom launched Atlantic Bastion, a broad initiative aimed at strengthening undersea threat monitoring and response across the North Atlantic, including protection of CUI. Atlantic Bastion seeks to integrate autonomous surface and underwater vehicles, crewed ships, aircraft, and advanced sensors into AI-enabled networks capable of detecting, tracking, and responding to undersea threats. While Atlantic Bastion extends beyond seabed infrastructure protection alone, it illustrates how undersea security is increasingly being approached as a systems problem rather than a platform-specific challenge. In 2026, further advances in seabed mapping, persistent sensing, autonomous inspection, and AI-enabled data fusion will continue shifting protection of CUI toward continuous, networked awareness and response rather than episodic patrols.The Finnish Navy vessel Hila with the Porkkala Coastal Battalion carries U.S. Marines with 2d Reconnaissance Battalion, 2d Marine Division During Operation Baltic Sentry in Southern Finland, Feb. 25, 2025. (U.S. Marine Corps photo by Lance Cpl. Brian Bolin Jr.)XL-AUV DeploymentWith Anduril’s Ghost Shark now a Royal Australian Navy (RAN) program of record, 2026 may mark the first year an extra-large autonomous underwater vehicle (XL-AUV) formally assumes an operational role. Early employment is likely to emphasize integration into fleet exercises rather than routine tasking, but this would represent a meaningful transition from demonstration to adoption. The RAN could emerge as an early reference model for how large autonomous undersea platforms can be incorporated into fleet operations at scale.Ghost Shark XL-AUV. Credit: AndurilBy contrast, the future of the U.S. Navy’s XL-UUV effort, Orca, remains uncertain. The Government Accountability Office (GAO) has questioned whether it will transition to a program of record, and in late 2025, reporting emerged that a draft Navy plan associated with the new Portfolio Acquisition Executive for Robotic and Autonomous Systems (PAE RAS) proposed canceling or redirecting funding for Orca as well as BlackSea Technologies’ Global Autonomous Reconnaissance Craft (GARC). Since Orca was conceived, Navy acquisition culture has increasingly emphasized expendability, commercial solutions, and rapid prototyping. While Orca is capable and carefully engineered, its size, cost, and complexity make it difficult to scale and somewhat ill-suited to this environment. Even if restructured rather than canceled outright, Orca may primarily function as a testbed, with its autonomy, endurance, and integration lessons informing future extra-large vehicle efforts. Although no direct replacement has been announced, the Defense Innovation Unit (DIU)’s call for a Combat Autonomous Maritime Platform (CAMP), a commercially available, demonstration-ready system for long-range, high-capacity payload delivery, appears at minimum to be a hedge against Orca’s uncertain trajectory.Graphic illustration of the Orca, an extra-large class Unmanned Undersea Vehicle, Naval Undersea Warfare Center Division Keyport was assigned as the In-Service Engineering Agent. (U.S. Navy Graphic/Released)DIU Accelerated ProcurementHigh-velocity procurement pathways, particularly through DIU, are likely to remain a defining feature of defense acquisition into 2026. This approach was evident in 2025 across multiple domains, including the undersea environment, with DIU’s calls for CAMP as well as low-cost undersea effectors. Earlier, in 2024, uncertainty surrounding the Snakehead program’s transition to a program of record led the Navy to pursue a COTS solution, selecting Oceaneering International to provide a large displacement unmanned undersea vehicle (LDUUV). This pattern of prioritizing fieldable capability over prolonged development cycles appears set to continue. Momentum is already carrying into 2026 with DIU’s call for an Autonomous Vehicle Orchestrator, a vehicle-agnostic, plain-language system designed to task, coordinate, and manage autonomous platforms at the fleet level. Structured as a $100 million challenge to be executed through a series of iterative vendor sprints, the effort reflects DIU’s intent to compress timelines, broaden vendor participation, and arrive at operationally relevant prototypes more quickly. These initiatives signal a continued shift away from monolithic programs toward an acquisition model aimed at delivering autonomy-enabled capabilities at speed and scale.Freedom AUV and Liberty Resident System Mobile Docking. Credit: Oceaneering InternationalIntegrated Mine Countermeasures (MCM)Last year marked several key milestones in the mine countermeasures (MCM) space. The U.S. Navy deployed its first operational Littoral Combat Ship (LCS) MCM mission packages, just as the last remaining Avenger-class MCM ship, USS Devastator, was formally decommissioned in September. In Europe, the Dutch Navy’s future mine countermeasures vessel HNLMS Vlissingen entered sea trials in early 2025, representing a new generation of robotic MCM platforms emerging from the joint Belgian–Dutch program to replace the Tripartite- and Alkmaar-class minehunters. At the payload level, NATO placed a multi-nation order for several hundred Exail K-Ster mine neutralization vehicles, reinforcing a shift toward standardized, unmanned MCM capabilities across allied navies.The merchant vessel Seaway Hawk sails in the Arabian Gulf while transporting decommissioned U.S. Navy Avenger-class Mine Countermeasures Ships, USS Devastator, USS Dextrous, USS Gladiator and USS Sentry. (U.S. Navy photo by Mass Communication Specialist 2nd Class Iain Page)As geopolitical instability persists in key maritime regions, MCM is likely to remain a high-level procurement and operational priority in 2026. Two potential flashpoints could see MCM forces operating in live environments this year: a post-conflict mine clearance effort in the Black Sea should a cease-fire in Ukraine prompt NATO involvement, or renewed MCM activity in the Persian Gulf if U.S. pressure on Iran intensifies following recent crackdowns. In both cases, assured access and freedom of navigation would hinge on the rapid deployment of effective MCM forces.In 2026, we will likely see increasing emphasis on interoperability at both the platform and payload levels to enable seamless coalition operations, driven in part by improvements in data fusion. MCM may also converge with broader undersea domain awareness and CUI protection missions, as the same sensors, platforms, tactics, and analytics used to counter mines are increasingly applied to monitoring seabed cables, pipelines, and port approaches.ContainerizationAs navies contend with aging fleets, constrained budgets, and rapidly evolving undersea threats, containerized payloads are emerging as a core naval architectural principle. Modular, mass-producible, platform-agnostic, and comparatively low-cost containerized systems offer a practical way to configure force packages with minimal impact on hull design or crew training. In 2025, the U.S. Navy reinforced this approach by soliciting industry proposals to rapidly prototype containerized payload unmanned surface vessels (USVs) capable of being fielded quickly and at scale. Under the Modular Attack Surface Craft (MASC) initiative, which consolidated the Navy’s Large and Medium USV programs, USVs are envisioned as standardized carriers for containerized payloads, including sensors, communications systems, electronic warfare equipment, and weapons. In 2026, containerization is likely to further solidify its role as a risk-reduction mechanism for naval procurement and force structure, with interest expanding into modular ASW, minelaying, MCM, and CUI defense systems. Industry players such as SH Defence, with its proprietary Cube plug-and-play mission modules, illustrate how containerization is enabling navies to field adaptable capabilities without committing to fixed platform architectures.Harder, Better, Faster, StrongerTrends emerging from 2025 point toward a maritime security environment defined by ruggedized, distributed, adaptable payloads, persistent awareness, and operational agility. As autonomy, modularity, and data-driven subsea operations continue to mature, 2026 will likely see navies prioritize flexibility, interoperability, and speed of integration over exquisite, single-purpose solutions. Whether addressing mine threats, protecting CUI, or countering uncrewed systems, success will increasingly hinge on the ability to sense, decide, and respond decisively across domains.