The Race for the Hybrid Fleet: Part 1
- Rui Costa
- Feb 5
- 12 min read
Updated: Apr 20
A New Vision for Fighting at Sea
Naval Warfare is rapidly evolving, driven by emerging technology, novel concepts of naval operations, and the ever-shifting landscape of global security challenges. At the forefront of this transformation, currently lies an ambitious vision of a future hybrid fleet – an integrated force of manned and unmanned naval assets designed to operate cohesively across all domains of maritime operations. This concept, previously limited to the realm of science fiction, is now becoming a tangible reality. Navies across the world have started to embrace autonomous technologies and artificial intelligence to enhance the capabilities of conventional crewed warships, and build the fleet of the future.
The United States Navy (USN) is one of the main drivers of this vision. In a 2022 address at the military-industry WEST conference, then-Chief of Naval Operations, Admiral Michael Gilday, revealed the USN’s goal to reach 500 ships by adding approximately 150 unmanned maritime vehicles to its inventory. This concept provided further clarity regarding the Navy’s UNMANNED Campaign Framework – which culminated in the issuance of the Chief of Naval Operations’ NAVPLAN and Force Design 2045 (both calling for 350 manned ships and 150 large unmanned maritime vehicles). Later, in 2023, Capt. Scott Searles, Program Manager, Unmanned Maritime Systems at the Naval Sea Systems Command (NAVSEA), had elucidated future plans for a Hybrid fleet which may even reach a 40-percent unmanned composition. This initial vision, was later bolstered in early 2024, when the new Task Group 59.1 was launched. This naval task group focuses on the operational deployment of unmanned systems teamed with manned assets to bolster maritime security across the Middle East.
Echoes of this unique vision have also resonated across Europe, with the European Defence Agency (EDA) recently reinforcing its commitment to the development and integration of unmanned assets into modern EU Forces. In November of 2024, the agency hosted its first Autonomous Systems Community of Interest (ASCI) Conference, following the approval of the EDA’s Action Plan on Autonomous Systems (APAS), earlier in January 2024. An action plan which already follows an impressive range of initiatives, from various European Defence Fund (EDF) funded assets currently in development (such as the EUROGUARD semi-autonomous surface vessel) to large-scale maritime unmanned systems experimentation exercises such as the yearly REP(MUS) in Portugal.
These bold moves reflect a significant shift in modern naval operations and leaderships’ future vision for these – one that promises not only to reshape the way naval forces operate but also to challenge our own vision of future naval fleet compositions, defence acquisition and technology development prioritization across the 21st century. In the words of Admiral Michael Gilday, “The hybrid fleet is not just about technology – it’s about creating a more lethal, distributed force that can prevail in any maritime theatre.” But what does this paradigm shift actually mean for the future of naval warfare, and how will it impact the dynamics of global naval power? How is NATO, its member states and allies, handling this new vision for fighting at sea – and how are its adversaries? And, ultimately, how will this impact the Defence Ecossystem as a whole – from large historically significant naval shipyards to small start-ups fresh off technology incubators?
This set of serialized articles will help our readers answer some of these questions – and perhaps raise a few new interesting ones. Across a three-part journey we will delve into the evolution of the hybrid fleet vision, examining the driving forces behind this strategical shift, the technological advancements underpinning this concept, and the challenges and opportunities it presents for navies and nations worldwide. We’ll journey across the world, further delving into Europe’s own current views on the “Hybrid-Fleet” concept, and how it diverges from its US-Counterpart. We’ll take a deep dive into where our geopolitical adversaries and threats currently stand within this unique field and vision – and how we actually match up to our perceived competitors. And, finally, we’ll journey across the myriad of challenges and opportunities surrounding this new vision for fighting at sea, through the eyes of the Defence & Security ecosystem as a whole. In this first edition however, we’ll start with a brief sightseeing tour across the Atlantic “pond”: all the way to the United States.
A Critical Strategic Shift
The U.S. Navy’s vision for a hybrid fleet comes as an inherent response to the growing complexity of modern maritime threats. Conventional naval vessels, while still critical to national defence, have been shown to be increasingly vulnerable to not only advanced naval weaponry (such as anti-ship missiles), but also to less-sophisticated asymmetrical threats employed by near-peer adversaries – a lesson particularly evident across the Ukrainian Conflict. Further lessons from Ukraine, have also shown that the threat-landscape within the Maritime domain is changing at a never-before-seen pace – demanding unprecedented agility, flexibility and future-proofing of naval assets and associated concepts of operation.
The Case for Distribution
To mitigate these risks, the US, and other allied Navies, aim to distribute their capabilities across a wider array of platforms, leveraging the advantages of unmanned systems to enhance operational flexibility and support an attritable and highly agile future fleet. One of the key elements of this strategy is the distributed lethality concept, which calls for spreading offensive and defensive capabilities across a larger number of smaller, attritable or expendable vessels.
Elaborating upon this notion, it involves re-designing naval force architectures. Instead of having a small number of highly complex and capable ships, with their own sensors and effectors, the U.S. Navy will spread out a fleet’s capabilities, including the aforementioned sensors and effectors, across a wide spectrum of assets, many of which are unmanned vessels. Each unmanned asset has its own unique role and capability which, when operating in a coordinated manner with other manned and unmanned assets, will make up the capabilities of a task force or fleet. This translates into a distributed capability network, far distant from most Navies’ current platform-centric fleet compositions and closer to a system of systems concept.
Compared to their manned counterparts, these Unmanned Vehicles (UV’s) are, at face-value, less expensive to procure, operate and modernize due to the nature of their design and lack of need to incorporate spaces and support equipment for on-board human operators. Additionally, these are also more suitable for long-duration missions (which tax the physical and psychological endurance of crews), they allow end-users to increase capability without being limited by the number of active duty military personnel to field ships and, crucially, are profoundly more expendable and replaceable. The inclusion of unmanned assets into modern fleets is however not meant to replace the entire capability range of highly sophisticated manned ships, but rather to augment it across a wider distributed spectrum that is more capable of handling the growing complexity of the modern naval battlefield.
Lessons from the U.S. Navy’s Unmanned System Programs
This is, of course, not an entirely novel concept. The U.S. Navy has already been setting the stage for this particular evolution for many years – and putting it to practice as well. UV’s, in the context of their broader operational use within both the U.S. Navy and allied NATO Nations’ Navies, can be subdivided into two key-archetypes/groups common for both Unmanned Surface Vehicles (USV’s) and Unmanned Underwater Vehicles (UUV’s):
Smaller-sized USV’s and UUV’s, which can be deployed from manned Navy ships and submarines, are generally used for specialized roles in order to extend the operational reach and capabilities of large crewed naval assets. These usually come in the range of 2 to 12-meter long surface vessels and 8 to 215-centimeter diameter underwater vehicles.
Medium to Large UVs, which are deployed directly from pier, tasked with missions or equipped with capabilities which are commonly and integrally linked to manned ships and submarines. These vessels are generally in the range of 12 to upwards of 50-meter long surface vessels and 215-centimeter plus diameter underwater vehicles.
Directly linked to this vision are two striking components which are clearly different from the approaches taken by most European Nations. Firstly, the pronounced and overarching “buy-in” for the distributed maritime operations concept and unmanned naval assets - as well as their application across a wide variety of operational roles. Secondly, the clear investment in the development, rapid implementation and scaling of not only small UV’s but also larger unmanned assets – such as medium and large USVs and XLUUVs.
The latter component, in the form of an evident push to develop and integrate large unmanned vehicles into the U.S. fleet, is entirely aligned with the U.S. Navy vision for a future distributed fleet architecture. The U.S. Navy had already begun experimenting with medium and large unmanned systems at scale, as early as 2016. One notable example is the Sea Hunter, a 132-foot autonomous surface vessel developed by DARPA (Defense Advanced Research Projects Agency), designed and built by Leidos, as a part of the Anti-Submarine Continuous Trail Unmanned Vessel Program (ACTUV) – on a budget of $20 million. The Sea Hunter, was designed to operate autonomously for months at a time, conducting long-range anti-submarine warfare missions without the need for a crew and carried with it a naval payload which was only previously found on manned ships.
Other Medium and Large Unmanned Surface Vehicle foundational work was carried out by the Department of Defense’s (DOD’s) Strategic Capabilities Office (SCO) within the context of the Ghost Fleet program – within which, the USV development effort is called Overlord. Ghost Fleet Overlord is a fleet of experimental unmanned surface vehicles which, as of January of 2024, consists of four ships: USV Ranger, USV Nomad, USV Mariner and USV Vanguard. These unmanned vessels, converted from commercial fast replenishment ships, have been outfitted with next-generation command and control systems, as well as a virtualised Aegis Combat System (the same found on USN Ticonderoga-class cruisers). All of these vessels were converted from commercially available ships, in order to allow them to operate autonomously. The vessels were designed as low-cost, high-endurance ships, which can be reconfigured with various modular payloads – including modular missile launch cells for SM-6 standard missiles.
Tangent to the development of initial prototypes, such as the Sea Hunter and Overlord USVs, the Navy has since built upon this foundational work across its Large Unmanned Surface Vehicles (LUSV) and Medium Unmanned Surface Vehicle (MUSV) programs. These programs are aimed at the research, development, acquisition and future integration of both medium and large-size unmanned surface vehicles into the U.S. Navy fleet.
The LUSV program envisions large surface vessels as being 200 to 300 feet in length, with displacements ranging from 1.000 to 2.000 tons – the rough size of a conventional corvette. These vessels are aimed at being low-cost, high-endurance, high-flexibility and re-configurability assets, able to carry modular mission payloads – with a key focus on anti-surface warfare and strike payloads, including anti-ship and land-attack missiles. Each LUSV will be equipped with a vertical launch system with 16 to 32 missile-launch cells. These vessels are aimed at enabling the Navy’s Distributed Maritime Operations (DMO) concept as well as complementing the manned combatant force by delivering increased readiness, capability and capacity at a fraction of the procurement and sustainment costs of similarly equipped manned naval ships.
In a parallel effort, the MUSV program seeks to acquire a range of ships with less than 200 feet in length, and displacements of less than 500 tons – the size of a conventional patrol craft. Much alike the LUSV program, the Navy wants MUSV’s to be low-cost, high-endurance and re-configurable ships designed to accommodate modular naval payloads. The operational role of these vessels however, differs slightly from the LUSV. The MUSV’s will be mainly used for Intelligence, Surveillance, Reconnaissance and Targeting (ISR&T), Counter-ISR&T and Information Operations (IO). A good example of the operational use of these vessels is in high-risk battle assessment and in “closing the kill-chain” (i.e. the process of networking sensors to effectors) without the use of manned assets. This program is being pursued as a rapid prototyping effort – and is currently awarded to L3Harris, for circa $35 million. It includes the development of a single MUSV prototype, with options to procure up to eight additional vessels.
Within the underwater domain, the XLUUV program, also known as the Orca Program, was established to procure UUV’s with diameters of over 84 inches to further increase the USN’s unmanned underwater capabilities. These assets are designed to be transported to a forward operating port and launched from pier - unlike their smaller counterparts which can be directly deployed from manned platforms such as Navy submarines or surface ships. Akin to its surface counterparts, these vessels are designed to accommodate a variety of modular naval payloads – which, among other capabilities, will allow these uncrewed submarines to deploy Hammerhead mines. The current program includes five XLUUVS, delivered by Boeing. The Navy expects to procure these assets at a rate of one per year between 2026-2029, with estimated procurement costs of $113.3 million, $115.6 million, $117.9 million, and $120.4 million, per unit, respectively.
In the range of small unmanned surface and subsurface vehicles, the U.S. Navy already has a range of assets in operational use. The Fleet-class USV, also known as the Common Unmanned Surface Vehicle (CUSV), is one of these unmanned assets- a small-sized USV, with a length of 12 meters and 7.7 ton displacement, designed to be deployed from the Freedom and Independence-class littoral combat ships. These unmanned vessels, procured at costs between 5 to 6 million US$ per unit, are employed in anti-submarine warfare, mine warfare and electronic warfare roles alongside the larger crewed littoral combat ships. The vessels are designed using a modular architecture, allowing for different mission configurations. In their mine countermeasures configuration, for example, the USV’s are deployed ahead of naval task forces where they tow a countermeasure system designed to emit acoustic and magnetic signals in order to detonate influence mines at a safe distance ahead of the larger manned naval ships. Textron Systems has been contracted to deliver 52 Fleet-class USV’s to the U.S. Navy, which have as of 2022 reached initial operational capability (IOC) allowing them to begin operating in the fleet.
Challenges beyond the Horizon
As promising as this concept of operations and systems are, they are not without challenges. As of 2024, both the Congressional Research Service and the United States Government Accountability Office have published a series of reports outlining recommendations and challenges to congress regarding the above described programs and strategic efforts. These reports have outlined a wide array of oversight issues for the United States Congress, which include: the analytical basis for the proposed fleet architecture including Large UV’s, the Navy’s own Concept of Operations (CONOPS) for these assets, various program risks, cost growth, schedule delays and acquisition strategy issues. Most of which are inherently linked to the need to increase the technical maturity of unmanned assets and their integration within both the U.S. Navy fleet and the overarching vision of naval strategic capability building.
More recently, as of November 2024, two U.S. Senators overseeing the Pentagon are directly urging U.S. Navy leadership to rethink plans for the LUSV program, citing critical concerns over the size and complexity of the envisioned vessels, associated program costs and delivery timeline - as well as a critical shortfall in the availability of Mk-41 compatible missiles to outfit all LUSV’s. A letter signed by Sens. Jack Reed, D-R.I. and Roger Wicker, R-Miss., who also lead the Senate Armed Services Committee, cited these and further issues with the aforementioned program. Capitol Hill has shown mixed responses to the LUSV since its inception in 2019, and have urged Navy officials to further elucidate how unmanned vessels fit into the service’s broader concept of operations - although still generally supporting the need for the development of the Navy’s future hybrid fleet concept. By contrast, the MUSV program has received more positive responses, following the success of the Ghost Fleet Overlord program. The Navy has recently successfully completed both a 720-hour power demonstration on these USV’s engine system, without any human intervention, corrective or preventive maintenance, as well as the first test of fueling at sea (FAS) without any human interaction on the receiving vessel.
Global Implications for the Future Hybrid Fleet
The hybrid fleet is not merely an incremental step in naval technology and warfare: it represents a fundamental transformation in how naval forces may operate in the decades to come. While challenges remain in fully realizing this vision (which, despite all, is still in its nascent stages), the potential benefits of a hybrid fleet and associated distributed concept of operations make these strides to achieve its full realization a fundamental element in modern naval strategy. As navies around the world take note of the U.S. Navy’s ambitions, the coming years will undoubtedly see more investments in unmanned systems, manned ships designed to take advantage of a hybrid fleet composition and all associated enabling technology.
Despite this, while the U.S. Navy is making very clear strides in this direction and is arguably the Navy which is on the closest path to its full realization, not all nations share the same vision. Following this, on the next editions of SWZ Maritime, we will journey through the visions of various Navies across the world in tackling the growing complexity of modern naval warfare and their own unique vision to the hybrid fleet concept and unmanned asset integration. Furthermore, we will also explore how changes in future fleet compositions will affect the Defence ecosystem as a whole, and how industry, academia and end-users can prepare to meet the challenges of the future of fighting at Sea.
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