By Robbin Laird
The Royal Australian Navy is crossing a dangerous bridge.
On one side sits the fleet it has today: three Hobart‑class air warfare destroyers, a diminishing number of Anzac‑class frigates, and a support structure increasingly strained by the weight of strategic demand. On the other side sits the fleet Australia intends to build: Hunter‑class frigates, general‑purpose frigates, optionally crewed large surface vessels, and eventually nuclear‑powered submarines under the AUKUS pathway.
The bridge between the two is long, narrow, and if navigated without imagination, a passage of genuine strategic vulnerability.
Yet this is precisely the kind of challenge that four decades of military transformation ought to prepare us for. In my recent retrospective on transformation, I argued that meaningful change in military capability does not occur when a new platform is delivered, but when an entire ecosystem of concepts, organisations, sustainment and training has been built around that platform through years of operational experience.
The most important lesson was simple: transformation is less about hardware and more about learning, and that learning almost always takes place in periods when forces are operating with imperfect, incomplete, and often heavily criticized capabilities.
Australia’s coming “hull gap” is usually framed as a problem to be endured until the new ships arrive. That framing not only underestimates the operational risk; it also misses the opportunity.
If we apply the lessons of recent transformation drawn from fifth‑generation airpower, tiltrotor aviation, software‑defined platforms, and maritime kill webs, the hull‑gap decade emerges as something else entirely: a strategically unique window in which Australia can learn how to build and fight a hybrid manned–unmanned fleet before the new hulls ever leave the shipyard.
The question is whether Australian defence institutions are prepared to treat this decade as a transformation laboratory rather than a holding pattern.
The arithmetic of the gap and why it matters
The arithmetic of Australia’s surface fleet over the next decade is unforgiving. Today the Royal Australian Navy fields three Hobart‑class destroyers and eight Anzac‑class frigates, giving it eleven principal surface combatants on paper. In practice, maintenance cycles, upgrades, crew generation, and the inevitable friction of naval operations mean that only a fraction of those hulls are ready for sustained operations at any given moment. One Hobart in deep maintenance and another in work‑up can leave a single destroyer available as the high‑end backbone of deployed presence. That is not a fleet. It is a token.
The problem is set to worsen before it improves. HMAS Anzac, the lead ship of the Anzac class, was decommissioned in 2024 after twenty‑eight years of service; HMAS Arunta is scheduled to decommission in 2026. The Anzac force that once numbered eight ships will soon drop to six, even as the first general‑purpose frigate is not expected to be delivered until 2029 and operational until 2030. The first Hunter‑class frigate is not expected to enter service until around 2032.
Official plans promise a larger and more capable surface fleet in the 2030s: three upgraded Hobarts, six Hunters, eleven general‑purpose frigates and six large optionally crewed surface vessels, with a follow‑on destroyer program to come.
But force design ambition does not dissolve near‑term arithmetic. Over much of the period from now through the early 2030s, the RAN will operate with fewer major hulls than it does today, in a more contested environment, with higher expectations from allies and a more demanding set of missions across the Indo‑Pacific.
Calling this merely a modernisation period understates the operational risk. Modernisation implies a broadly linear substitution of old platforms with new ones. A hull gap is something different: a trough in which numbers fall before they recover. During that trough, commanders must do more with less, accept reduced surge capacity, and make sharper trade‑offs between presence, deterrence, training and readiness. The danger is not only that Australia will have fewer ships. It is that the few ships it does have will be too valuable and too stressed to be used as instruments of experimentation and learning.
If the hull‑gap decade is treated simply as a period to be endured, the new Hunter‑class and general‑purpose frigates will arrive in a Navy that is still thinking in legacy terms. The force will then face the hardest possible task: simultaneously absorbing major new platforms while trying to invent hybrid‑fleet concepts on the fly, in a deteriorating strategic environment.
The record of past transformation efforts suggests a better way.
What past transformations teach about transitional decades
In Lessons in Military Transformation, I drew on more than four decades of observing and documenting how real militaries adapt. From fifth‑generation airpower to the tiltrotor enterprise and software‑defined airlift, several patterns recur with clear relevance to Australia’s present challenge.
Transformation takes decades and belief is harder than technology
The story of fifth‑generation combat aircraft is not primarily a story of technology, but of belief. The F‑22 and F‑35 both demonstrated clear performance advantages early, yet it took almost two decades for air forces and their political masters to internalize what those advantages meant for operations. The most stubborn obstacle was the “belief gap”: the difficulty of accepting what one has never seen.
As I noted in discussing the F‑35’s evolution and Israel’s Operation Rising Lion, the real transformation only occurred when operators, planners and commanders began to assume fifth‑generation capabilities as the starting point for operations rather than treating the F‑35 as one option among many in a legacy force‑mix. That shift required years of flying, exercising, experimenting and, crucially, making mistakes. It could not be short‑circuited by better PowerPoint slides.
The same temporal reality held for the V‑22 Osprey. From initial concept to operational maturity took decades. Yet by the time Marine Expeditionary Units in the Pacific were treating the Osprey as a central connector for distributed operations rather than a helicopter replacement, the platform had enabled unanticipated changes in the geometry of operations, precisely because operators had had time to discover what it could really do.
The lesson is clear: the time between the arrival of a new capability and genuine transformation is measured in years, often a decade or more.
That time must be used to build belief, not merely to iron out technical bugs.
Ecosystems matter more than platforms
Another core lesson concerns what actually transforms a force. The F‑35’s most profound impact has not been as a platform, but as a centerpiece of a fifth‑generation ecosystem: shared mission data files, software‑defined communications, integrated sustainment, and a training architecture that generates a common operational language across services and allies. The same applies to the A400M airlifter, whose software‑enabled growth and multinational commonality created a platform that continuously evolves within an ecosystem of operators.
In the tiltrotor case, what transformed Marine aviation was not simply the appearance of a new airframe, but the combination of improved sustainment (the “nacelle revolution”), revised training, evolved operational concepts, and international expansion. Separating transformation from sustainment, or treating the latter as an afterthought, was a conceptual error exposed by operational reality.
The pattern is unmistakable: transformation succeeds when ecosystems are deliberately built around new capabilities, encompassing sustainment, data architectures, command‑and‑control, and training. It fails when a new platform is dropped into an unchanged institutional environment.
Operational experience is the irreplaceable currency
A third lesson is that operational experience cannot be bought, reverse‑engineered, or shortcut. Israel’s F‑35 force gained a decisive edge not merely through hardware, but through the accumulation of thousands of combat flight hours, enabling continuous refinement of tactics and concepts. The tiltrotor community’s journey from a controversial program to an indispensable capability similarly hinged on repeated deployments and a cadre of practitioners who learned through doing.
In each case, it was this operational learning that created what I have called “adaptive dominance”: the ability to stay one step ahead of adversaries by continuously updating how capabilities are employed, not just what capabilities exist.
The move from linear kill chains to resilient kill webs has been central to the transformation of maritime and air operations. Rather than thinking in terms of a single platform executing a sequence of detect‑identify‑target‑engage, kill webs envisage multiple nodes — manned and unmanned — contributing to and drawing from a shared information network. Disrupting one link no longer breaks the chain; the web re‑routes around it.
Fifth‑generation aircraft, integrated air and missile defence ships, distributed sensors, and autonomous systems all feed into this architecture.
The force design question shifts from “how many of each platform do we need?” to “what network topology and data flows do we need to achieve resilient effects?”
Finally, transformation is always embedded in politics and acquisition systems. The F‑35’s near‑death experiences owed as much to narratives about cost and complexity as to any technical issue. The tiltrotor program survived early accidents and criticism only because operational champions, incremental demonstrations and institutional persistence created a constituency for the capability.
Crucially, the acquisition and sustainment models used for new capabilities can either align with the way those capabilities actually deliver value or fatally constrain them. In the unmanned arena, the difference between treating systems as data‑services platforms (as with ScanEagle) and as traditional platform‑ownership programs (as with the failed Blackjack experience) has been decisive.
Australia’s autonomous capabilities: the foundations of a hybrid fleet
Against this backdrop, the Australian picture looks very different from one of pure vulnerability. Australia already has production‑scale autonomous maritime capabilities in service and under contract. The question is how it uses them.
The Ghost Shark large autonomous underwater vehicle is in steady‑state production under a multi‑year contract, with dozens of vessels being delivered annually. The program is built around a continuous upgrade architecture driven by user feedback, embodying the kind of software‑defined, iterative evolution that has characterized successful transformation in other domains.
Above the waterline, the Blue Bottle uncrewed surface vessel is under a production contract for forty vessels over five years, building on operational experience accumulated through more than 240 Maritime Border Command missions. Those missions have already driven performance from roughly 30‑day endurance to deployments exceeding 100 days at sea, with the platform functioning as a persistent sensor node in a distributed mesh.
These are not experimental prototypes waiting for doctrine to catch up. They are operational capabilities generating real data about what autonomous systems can do in real maritime environments. They are, in other words, the beginnings of a hybrid‑fleet ecosystem that exists now, during the hull‑gap decade, rather than in some future far beyond it.
The Royal Australian Navy has also created a Maritime Autonomous Systems Unit (MASU), which, if empowered appropriately, could become the institutional laboratory in which hybrid‑fleet concepts are developed, tested and refined at speed.
Put bluntly: the building blocks for a hybrid Australian fleet already exist. They are being produced, deployed and iterated. The challenge is not technological readiness. It is whether the Navy and the broader defence enterprise will use the hull‑gap decade to learn how to integrate these systems into a coherent operational architecture.
Three missions that cannot wait and should become laboratories
The most effective way to drive transformation, as I have repeatedly argued, is to anchor it in concrete operational problems rather than abstract futures. In Australia’s case, three mission areas stand out as both urgent and ideally suited to hybrid‑fleet learning.
- Defending HMAS Stirling: protecting submarines before they arrive
HMAS Stirling near Perth will eventually host some of the most strategically consequential assets in Australia’s history: visiting and then sovereign nuclear‑powered submarines. The base is already facing a diverse and layered threat picture: long‑range ballistic and cruise missiles, autonomous surface and underwater vehicles, drones launched from commercial vessels acting as covert platforms, and cyber and electronic attacks on the base’s supporting infrastructure. The possibility that a relatively low‑cost unmanned system could damage or disable a high‑value submarine at its berth represents a catastrophic return‑on‑investment failure.
The defensive architecture needed to mitigate this risk is not speculative. It will include layered air defence, counter‑drone systems, underwater barrier operations, and surface surveillance meshes. What is missing is the operational experience of integrating these elements — manned and unmanned — into a coherent kill web.
The hull‑gap decade is precisely when this learning should occur. Ghost Shark can provide subsurface reconnaissance and trip‑wire functions; Blue Bottle can extend the base’s surface sensor horizon, acting as the outer ring of a distributed detection network; crewed ships and aircraft can be cued by autonomous nodes rather than acting as the sole detectors. The base becomes not just a support facility, but a live laboratory for multi‑domain kill‑web defence. Lessons learned there can then be exported offensively to bottle up adversary submarines at choke points, just as early F‑35 and V‑22 operational experience informed later high‑end concepts.
- Northern waterspace management: extending the fleet’s reach
A second mission concerns the management of waterspace to Australia’s north, across a vast Indo‑Pacific geometry stretching from the archipelago to the Philippines and toward Taiwan. Critics sometimes argue that Australian autonomous systems lack the reach for strategically relevant operations. Operational experience suggests otherwise. Industry is already producing systems whose range, depending on payload and configuration, allows them to operate from Australian territory into these northern approaches.
The real constraint is not range but the development of operational concepts, command‑and‑control architectures, and integration with crewed platforms and land‑based sensing. In the air domain, the A400M and F‑35 enterprises have shown how software‑defined platforms and shared data architectures can fundamentally alter operational tempo and reach. Maritime operations can follow a similar trajectory if autonomy is used to build persistent sensing and strike webs that extend the effective footprint of a small number of crewed hulls.
During the hull‑gap decade, the RAN can begin building this northern waterspace management architecture with the fleet it has: Hobarts and Anzacs acting as command and fire nodes, autonomous surface and subsurface vessels providing the outer layers of detection and tracking, and land‑based systems contributing to a fused picture. Every deployment becomes an experiment in hybrid operations, with MASU capturing and feeding back lessons at speed.
- Persistent mesh surveillance: the Blue Bottle as pixel, not patrol boat
The third mission is already the most advanced: persistent maritime surveillance at scale, as demonstrated by Maritime Border Command’s use of Blue Bottle USVs. The mesh‑fleet concept that Ocius has been developing, multiple autonomous surface vessels operating as a distributed sensor network, where the loss of a single node does not degrade the mission, represents a fundamentally different architecture for maritime surveillance.
As one Ocius executive put it, if you lose a Blue Bottle you have lost a pixel on a screen, but the mission continues; your other pixels remain. This is an inversion of the traditional capital‑ship logic, in which a flagship at the centre of a formation is both the primary source of command authority and the most valuable (and vulnerable) target. In a mesh, value is distributed and resilience emerges from redundancy rather than mass.
This is precisely the kind of conceptual shift that transformation requires.
The hull‑gap decade offers the chance to extend the mesh concept from border security to broader Indo‑Pacific operations, integrating Blue Bottles into naval task groups, using them to provide persistent coverage of key sea lanes, and fusing their data with other sensors. The aim is to habituate commanders and watch‑keepers to thinking in terms of webs and pixels, not just hulls and patrol patterns.
Building the hybrid fleet before the new hulls arrive
If these missions are treated as laboratories rather than marginal tasks, the hull‑gap decade can become the period in which Australia builds the cognitive, institutional, and industrial foundations of a hybrid fleet. Several lines of effort follow directly from past transformation lessons.
Make MASU the operational crucible, not a side project
First, MASU should be empowered and tasked as an operational crucible, not a technology incubator on the periphery of “real” naval business. Its purpose should be to solve genuine operational problems assigned by fleet commanders using fielded systems, with authority to rapidly iterate tactics, techniques and procedures based on operational feedback.
Industry leaders have warned that the “operational voice needs to be louder than the acquisition voice” in this space; at present, acquisition logics centered on platform delivery risk overpowering the need for rapid, data‑driven experimentation. Past transformation efforts suggest that this imbalance can be fatal. Where operational champions were empowered (as with the tiltrotor community and later F‑35 integrators), transformation survived turbulence. Where acquisition structures dominated and treated platforms as static assets (as in some failed unmanned programs), potential was squandered.
Institutionalize continuous upgrade and data‑centric procurement
Second, Australia should deliberately adopt acquisition and sustainment models for autonomous systems that align with their software‑defined nature. The value of Ghost Shark and Blue Bottle lies not primarily in their hulls, but in the payloads they carry, the data they generate, and their ability to be continuously upgraded. This argues for contracts organized around data services and mission availability (days on station, quality and timeliness of situational awareness) rather than one‑off platform purchases with long, infrequent upgrade cycles.
The hull‑gap decade is the ideal time to experiment with such models, because the stakes and sunk costs are lower than they will be once large numbers of crewed hulls arrive. The lesson from A400M and F‑35 is that building in software‑enabled growth from the outset creates a different ownership model—and a different mindset among operators—than trying to retrofit flexibility into a legacy acquisition framework.
Train the existing fleet to fight hybrid
Third, the RAN should use its existing crewed hulls as training platforms for hybrid operations. Hobarts and remaining Anzacs can be treated as “motherships” that routinely deploy with autonomous screens: Blue Bottles operating as forward pickets, Ghost Sharks as subsurface scouts, other systems as communications relays and decoys. Watch‑keepers, COs and task group commanders should grow accustomed to commanding webs of manned and unmanned assets, not just traditional formations.
This is precisely what institutions like MAWTS‑1 does for Marine aviation, becoming cognitive laboratories in which Marines learned to think in terms of distributed, multi‑domain operations rather than linear close air support. The earlier such training begins, the more natural hybrid thinking will be when new hulls arrive.
Build industrial depth and allied interoperability around autonomy
Fourth, Australia should treat its emerging autonomous maritime industry as a strategic asset in its own right. The Blue Bottle is built substantially around commercial off‑the‑shelf components, with a supply chain that is broader, more resilient, and more easily mobilized than those required for capital ships. Ghost Shark production similarly taps into a different industrial base than traditional naval construction.
Using the hull‑gap decade to deepen these industrial ecosystems through sustained demand, workforce development, and integration into allied supply chains will pay dividends decades beyond the arrival of Hunter‑class frigates. Past experience with tiltrotor and A400M enterprises shows that international interoperability built around shared platforms and software architectures can multiply operational impact far beyond what any single nation can achieve. The same could hold for autonomous maritime systems if Australia positions itself as a key node in a broader coalition enterprise.
From bridge to destination
The hull‑gap decade is often described as a bridge: a necessary crossing between an aging fleet and a more capable one. Bridges, however, are not neutral spaces. They are places where forces can be caught exposed, where missteps can prove catastrophic.
They are also, in the history of military transformation, moments when practitioners either seize the opportunity to learn faster than their adversaries or retreat into risk aversion and nostalgia.
The lessons of recent transformation efforts suggest that Australia has a choice. It can treat the hull‑gap decade as a waiting room, husbanding scarce hulls and deferring real experimentation until new ships arrive. If it does so, the arrival of those ships will mark the beginning of a long, painful process of learning hybrid warfare under pressure. Alternatively, it can treat the decade as a transformation laboratory, using the autonomous capabilities it already has, the missions it already faces, and the institutions it has begun to build to prototype the hybrid fleet in practice.
In the language of Lessons in Military Transformation, the most important shift is cognitive. Australia must move from asking, “How do we get through the next ten years until the new fleet arrives?” to asking, “How do we use the next ten years to ensure that when the new fleet arrives, it joins a force that already knows how to fight as a hybrid, kill‑web navy?”
The hull‑gap decade will not come again.
The frigates and submarines now on the drawing board will not wait for doctrine to catch up.
The foundations of the hybrid fleet will be laid either now, with the imperfect capabilities at hand, or later, under more adverse conditions.
The experience of past transformation makes one thing clear: waiting for perfect platforms before learning how to use them is a luxury no serious maritime power can afford.