Sea-Air-Space 2026 marked a clear turning point for the maritime
defense industry. The main message was that naval innovation is moving
from experimentation to fielded capability. With more than 16,000
attendees, 57 countries, and around 430 exhibitors, the exhibition
showed that maritime power is once again central to global security,
deterrence, logistics, undersea infrastructure, and great-power
competition.
The key strategic theme was the emergence of a “Golden Fleet”
concept: a high-low force structure combining large, survivable
command-and-strike ships with distributed autonomous systems,
information warfare, and a more resilient industrial base. The proposed
BBG(X) battleship concept symbolized the return of mass, magazine depth,
electrical power, and survivability as decisive factors in future naval
warfare.
Autonomy was another dominant theme. Systems such as HII’s ROMULUS
USV, Saildrone’s 52-meter Spectre, Anduril’s Dive family, Ocean Aero’s
Triton, and General Atomics’ UUV showed that unmanned systems are no
longer side projects.
They are becoming operational fleet components designed for
persistence, reach, sensing, and distributed effects.
The exhibition also highlighted a shift in sensor strategy. While no
major new sonar launch stood out, the focus moved toward integrated
sensor architectures, layered torpedo defense, resilient navigation,
ISR, autonomy stacks, and combat-system integration. In short, the value
is no longer in the sensor alone, but in how it connects, processes, and
contributes to decision advantage.
The final takeaway is provocative but simple: the future fleet will
not be defined by one perfect ship, drone, or sonar. It will be defined
by integration, production scale, software speed, and operational
relevance. A platform without payload, data links, autonomy, and a real
concept of operations is no longer a capability. It is just expensive
displacement.
Sea-Air-Space 2026 did not feel like a normal defense exhibition. It
felt like the maritime industry being told, politely but firmly, that
PowerPoint season is over.
The show brought together more than 16,000 attendees, 57 countries,
and around 430 exhibitors. That scale matters. It shows that the
maritime domain is no longer a specialist corner of defense thinking. It
is central to deterrence, logistics, energy security, undersea
infrastructure, and great-power competition. The sea is back on the
strategic menu, and not as a side dish.
[Video: Video Overview of SAS 2026]
From Experimentation
to Fielded Capability
The strongest message from the exhibition was simple: the era of
experimental autonomy is ending. The era of fielded capability is
beginning.
For years, naval autonomy has been filled with elegant renderings,
controlled demonstrations, and carefully polished future roadmaps. At
Sea-Air-Space 2026, the conversation shifted. The question was no
longer, “Can it work?” The question became, “Can it be produced,
integrated, updated, deployed, and sustained at scale before the next
crisis removes the luxury of choice?”
That is a very different question.
The big strategic theme was the move toward what some are calling the
“Golden Fleet”: a high-low maritime architecture built around large,
survivable command-and-strike platforms, distributed autonomous systems,
information warfare, and a more resilient industrial base. In plain
English: big ships for power, unmanned systems for reach, software for
speed, and distributed shipbuilding for volume.
The Return of Mass
The most provocative symbol of this transition was the proposed
BBG(X), the so-called Trump-class battleship concept. Whether one loves
or hates the idea of bringing back the capital ship, the logic behind it
is worth understanding.
Modern naval combat is becoming a brutal equation of range, magazine
depth, electrical power, survivability, and the ability to command
distributed assets. Smaller platforms may simply not have enough margin
for hypersonic weapons, directed energy, railguns, aviation capacity,
and command-and-control all at once. At some point, physics becomes very
impolite.
The BBG(X) concept is therefore less about nostalgia and more about
volume. More displacement. More power. More weapons. More margin. The
idea is to stop merely “swatting arrows” and start “killing the archer.”
That phrase may be provocative, but it captures the strategic shift from
defensive interception toward offensive sea-control dominance.
Autonomy Moves to the
Production Line
But the show was not only about large combatants. In many ways, the
more important story was autonomy moving from the marina to the
production line.
HII’s ROMULUS USV program stood out because it represents exactly
this shift. Four AI-enabled ROMULUS 151 vessels entering production is
not just another unmanned surface vessel announcement. It is a signal
that USVs are becoming fleet components, not science projects. The
integration of Warship OS with Applied Intuition points toward
coordinated autonomy, common control, and faster mission updates across
multiple platforms.
HHI ROMULUS USV
Saildrone’s Spectre also attracted attention. At 52 meters, it pushes
the USV category into a different conversation. This is not a small
harbor demonstrator. It is a persistent, open-ocean platform with
payload capacity, endurance, and strategic relevance. The direction is
clear: uncrewed surface vessels are growing up.
Saildrone Spectre
Below the surface, the exhibition also confirmed strong momentum in
UUVs and hybrid autonomous vehicles. General Atomics displayed its
electromagnetic UUV. Ocean Aero showed its Triton autonomous underwater
and surface vehicle. Anduril presented elements of the Dive-LD and
Dive-XL family. HII reinforced its long position in the unmanned
undersea market, including the continued relevance of REMUS after 25
years.
Sensors Are Becoming Systems
Interestingly, there was no major new sonar release at the event. For
a sonar person, that is always a little disappointing. We like new shiny
arrays. Preferably wet, expensive, and difficult to explain at cocktail
parties.
But the absence of a dramatic new sonar launch does not mean the
sensor story was weak. The sensor story was integration. Ultra Maritime
highlighted layered torpedo defense. SBG and Honeywell showed navigation
and inertial sensing products for autonomous platforms and
high-vibration environments. Exail and Leonardo DRS focused on ISR,
autonomy, and naval combat systems.
That is the real lesson. Sensors are no longer isolated boxes bolted
onto platforms. They are part of a combat system, a data architecture,
and increasingly an autonomy stack. A sonar without integration is just
an expensive underwater microphone with good manners.
The Uncomfortable Truth
The information warfare discussion reinforced the same point. The
IWRON construct moves intelligence, cyber, oceanography, and electronic
warfare closer to the center of fleet operations. That is not
bureaucracy. That is recognition that the next naval fight may be won or
lost in the data layer before the first missile leaves the rail.
Sea-Air-Space 2026 showed a naval force in transition from elegance
to mass, from experimentation to deployment, and from platform obsession
to system integration.
The maritime future is not autonomous, manned, surface, undersea, or
airborne.
It is integrated.
And anyone still selling “a platform” without the payload, software,
data link, concept of operations, and production strategy is not selling
the future.
They are selling a very expensive floating apology.
Why
the Smallest Submarines May Be the Biggest Problem in Coastal
Warfare
For decades, naval prestige has favored scale. Bigger submarines.
Bigger combat systems. Bigger sensor suites. Bigger budgets.
But coastal warfare has never cared much about prestige.
In the shallow, noisy, cluttered waters where chokepoints, ports,
shipping lanes, and critical infrastructure converge, the modern midget
submarine is making a very uncomfortable comeback. Not because it is
elegant. Not because it is glamorous. But because it is useful.
That is often how real threats work.
Small Hull. Big Strategic
Effect.
A midget submarine does not need global reach. It does not need
months of endurance. It does not need a brochure full of exquisite
blue-water capability.
It only needs to survive long enough, in the right place, to create
operational or strategic effect.
That is what makes these platforms dangerous. Their small size, low
acoustic profile, and ability to operate in seabed clutter allow them to
exploit what I would call the littoral shadow: the messy acoustic space
of shallow water, coastal traffic, thermal variability, biological
noise, and bottom reverberation where traditional anti-submarine warfare
becomes far less elegant.
In blue water, detection theory looks clean. In the littorals, it
often looks like a bad compromise.
And that is where these mini/midget submarines thrive, laying
undetected on the sea floor.
An Old Concept That
Never Really Went Away
The idea is not new. The Japanese Type A, British X-Class, German
coastal mini-subs, and the Italian human torpedo program all proved
during the Second World War that a very small undersea platform could
achieve an effect wildly disproportionate to its size.
Harbor penetration. Mining. Ambush. Sabotage. Covert insertion.
Strikes against capital ships in protected waters.
The details have changed. The logic has not.
What has changed is the modern operating environment. Today’s
maritime battlespace is dense with coastal infrastructure, narrow
straits, offshore installations, surveillance gaps, and political
gray-zone activity. In that environment, small submarines are not
relics. They are highly rational tools.
The Proliferation Chain
Matters
This is not just a story of submarine design. It is also a story of
proliferation.
Post-war Italian designs, particularly those associated with Cosmos,
provided a technical foundation for compact littoral submarines. North
Korea adapted elements of that small-submarine logic into classes such
as the Yugo and later the Yono. Iran then followed with the
Ghadir-class, which shares a very similar tactical philosophy and
reportedly similar design lineage, while also expanding its undersea
portfolio with the Nahang and Fateh classes (Ghadir is basically a
stretched North Korean mini-sub). North That progression matters because
it shows how a niche capability became a practical regional warfare
tool.
North Korea helped demonstrate what a compact submarine could do in
real conflict. Iran has taken that lesson and applied it to one of the
most strategically sensitive maritime environments on earth: the Persian
Gulf and the Strait of Hormuz.
North Korean Mini-Submarine
That is not a minor detail. That is the whole point.
The
Ghadir-Class: Compact, Constrained, and Dangerous
The Iranian Ghadir-class is a good reminder that limited size does
not mean limited lethality.
Because of space and weight constraints, the boat reportedly relies
on a single hull-mounted passive sonar array operating in the
medium-frequency range of around 1 to 10 kHz. That gives it a basic but
operationally relevant ability for contact detection, target
classification, and beamforming. No large towed arrays. No sophisticated
sonar payloads.
But this is where people make the wrong comparison.
Iranian Gharid Mini-Submarine
The Ghadir should not be measured against a blue-water attack
submarine. It should be measured against its intended operating
environment: shallow, congested, tactically compressed waters where
engagements are short, clutter is high, and reaction time is limited. As
it is shallow water, there is a cut-off frequency, making long passive
towed arrays useless.
Iran has also compensated for sonar limitations by fielding a
modernized optical and electronic sensor suite. The submarine is
reported to carry an advanced periscope fitted with thermal imaging, day
and night television cameras, and a laser rangefinder, all feeding
digital displays in the control room. It also features a mast-mounted
short-range air search radar, giving it improved awareness of
helicopters and aircraft while minimizing exposure above the
surface.
That matters. In shallow-water operations, situational awareness is
often more important than elegance.
The Weapons Fit Is
Where It Gets Serious
The Ghadir-class is built around two 533 mm torpedo tubes, and that
alone makes it a credible ambush platform in restricted waters.
It can reportedly deploy conventional heavyweight torpedoes such as
the Valfajr, but the more provocative weapon is the Hoot supercavitating
torpedo, intended to reach extremely high speeds and compress reaction
timelines. Whether every published performance figure is fully reliable
is almost beside the point. The tactical signal is clear. This platform
is designed to create chaos at short notice.
More important still is the reported ability to launch submerged
anti-ship cruise missiles, including the Jask-2, which gives the
submarine a covert standoff strike option. Add the ability to lay naval
mines, and the Ghadir becomes far more than a coastal nuisance.
It becomes a compact A2/AD tool.
Not a fleet submarine. A denial submarine.
And in the Persian Gulf, that distinction matters a great deal.
Why Sonar
Specialists Should Pay Attention
From a sonar perspective, this is a very annoying target set.
Shallow water is unforgiving. Reverberation is high. Bottom
interaction is messy. Shipping clutter is everywhere. Biological noise
is rarely helpful. And a small submarine operating slowly, with low
cavitation and limited need to expose itself, becomes difficult not only
to detect but to confidently classify. If it sits on the sea floor,
almost impossible to detect with standard ASW sonars.
That is the key issue.
Detection is cheap. Understanding is expensive.
A midget submarine sitting quietly in the seabed environment is not
just hard to find. It is hard to confirm, track, and act against without
wasting time, platforms, and decision bandwidth. That is exactly what a
smart regional denial strategy wants.
This is why large-navies-with-large-sensors should not feel too
comfortable. The littorals are where elegant ASW concepts go to have a
very bad day.
The Real Counter:
Persistence Beats Prestige
The answer is not simply more frigates, more helicopters, or more
expensive crewed platforms rotating through the same waters.
The answer is persistence, 24/7 persistence.
Persistent monitoring with uncrewed surface vessels. Persistent
subsea surveillance. Smarter seabed sensors. Better acoustic libraries.
Better classification workflows. Better fusion between autonomous and
crewed assets.
You do not beat the littoral shadow with occasional brilliance.
You beat it with systems that stay on station longer, listen better,
classify faster, and make the water less forgiving for a boat trying to
disappear.
That is where the future fight is heading.
Closing Statement
The smallest submarines are not dangerous because they outperform
blue-water boats across the board. They are dangerous because they are
optimized for the exact waters where many navies are least comfortable
fighting.
Small hull. Short profile. Strategic consequences.
That is not yesterday’s threat. It is already here.
Please comment, so we all can learn from each other.
This is a video that complements the article I wrote Yesterday. Here
is the link to my article:
https://www.linkedin.com/pulse/strategic-ping-china-just-deploying-uuvs-mapping-silence-meurling-o2slc
The recent recovery of a Chinese UUV in the Lombok Strait should not
be treated as a strange maritime footnote. It should be treated as a
warning.
Because this was never just about one unmanned vehicle drifting into
the wrong place. It was about what that vehicle was likely doing before
it was found. And that matters a great deal.
Chinese UUVs
For those of us who have spent years working with sonar, seabed
mapping, underwater surveillance, and the brutal realities of acoustic
performance, the signal is obvious. China is not only investing in
undersea platforms. It is investing in understanding the water itself.
That is a much bigger strategic issue.
The undersea battlespace is changing. Quiet platforms still matter.
Stealth still matters. But stealth is no longer just about hull design,
propulsion, or signature reduction. It is increasingly about who knows
the environment best.
And in chokepoints like Lombok, the environment is the weapon.
The Lombok Strait is not just another narrow passage in Southeast
Asia. It is one of the few deep-water routes through the Indonesian
archipelago that can support submarine transit at meaningful operational
depth. That alone makes it strategically interesting. Unlike shallower
alternatives, Lombok offers a valuable acoustic corridor for movement
between the Pacific and Indian Oceans. If you want to understand where
submarines can move quietly, where they may hide, and where their
acoustic advantage may begin to weaken, this is exactly the kind of
place you study.
Relentlessly.
That is why the technical payload matters more than the paint job or
the logo on the hull.
A UUV operating in such an area is not just collecting data. It is
building a model of the battlespace. With the right sensor package, it
can measure currents, water column structure, seabed topography, ambient
noise, and acoustic variability over time. In plain language, it can
help answer the questions every submarine commander and every ASW
planner cares about.
Where does sound bend?
Where does it die?
Where does the sound travel well?
Where can a submarine disappear?
And where can a submarine be found?
An Acoustic Doppler Current Profiler does not just measure current
speed. It helps define the movement of the water itself, including
layering and flow conditions that affect station-keeping, sensor
performance, and long-endurance loitering. Temperature and salinity
sensors do not just produce oceanographic charts. They define
thermoclines, haloclines, sonic layer depth, and transmission loss
behavior. That means they help predict where sonar performs well and
where it does not. Side-scan sonar is not just for pretty seabed
pictures. It helps characterize bottom type, terrain complexity, and
bathymetric features that may support covert movement or influence
acoustic clutter. Ambient noise monitoring helps separate biological,
hydrodynamic, and commercial noise from actual targets, which is
essential if you want to refine detection thresholds and improve
acoustic libraries.
This is where the discussion often gets too polite.
We still hear people describe these kinds of deployments as
scientific, exploratory, or dual-use. That is technically true in the
same way that a rangefinder can be used for golf or gunnery. Context
matters. Intent matters. Pattern matters.
And the pattern is clear.
China is steadily building the foundations for a more transparent
undersea battlespace. Not transparent for everyone. Transparent for
them.
That is the strategic point. If you can characterize the acoustic
properties of key chokepoints, deep-water approaches, and naval transit
corridors, you begin to reduce uncertainty. If you reduce uncertainty,
you reduce the value of your adversary’s stealth. If you reduce the
value of stealth, you begin to shift the balance of undersea
deterrence.
That is not a research project. That is preparation.
The Lombok recovery also matters because it fits into a broader
trend. This is not about a single vehicle, a single transit route, or a
single regional incident. It is part of a larger push toward
distributed, persistent, autonomous undersea sensing. The goal is not
simply to place more hardware in the water. The goal is to create a
better acoustic picture over wider areas, over longer periods, with less
human presence and lower political visibility.
That last point is important.
Archipelagic states and maritime democracies face a difficult
challenge here. Surface intrusions are visible. Airspace incursions are
visible. Even fishing militia can be photographed and named. But
undersea data collection sits in a murkier zone. It is often
non-kinetic. Often deniable. Often wrapped in the language of marine
science or civilian research. That makes it attractive. It also makes it
dangerous.
Because by the time the real purpose is fully understood, the data
has already been collected.
So what should serious maritime nations do?
First, stop treating Undersea Domain Awareness as an optional luxury.
It is becoming a baseline requirement.
Second, invest in fixed and distributed acoustic monitoring across
critical corridors, ports, and seabed infrastructure zones. Not as Cold
War nostalgia, but as modern layered sensing architecture.
Third, expand the use of multi-static and bi-static sonar concepts
for detecting low-observable unmanned systems that do not behave like
traditional submarines and do not present a convenient surface
signature.
Fourth, establish disciplined recovery, exploitation, and technical
intelligence procedures for foreign unmanned systems. Every recovered
vehicle is not just an incident. It is a floating database.
And finally, accept a hard truth. If your competitor is persistently
mapping the acoustic environment in peacetime, they are not preparing
for scientific dialogue. They are preparing for positional
advantage.
The undersea domain used to favor the side that could hide best.
Now it increasingly favors the side that has measured the water
first.
How
USV–AUV Mothership Operations Are Redefining Protection of Critical
Underwater Infrastructure
Critical Underwater Infrastructure (CUI), subsea pipelines, power
cables, and global communications links form the invisible foundation of
modern society. These assets that carry energy, data, and provide
economic stability across oceans are quietly enabling everything from
national defense to daily digital life, whilst also becoming
increasingly vulnerable.
The sabotage of the Nord Stream pipelines in 2022 and the damage to
the Baltic pipeline in 2023 did more than disrupt energy flows. These
incidents revealed that much of the critical seabed infrastructure
remains unprotected, insufficiently monitored, and difficult to defend
via traditional maritime surveillance.
What makes the challenge even more complex is the nature of the
threat. Many hostile actions targeting CUI fall into the “grey zone”.
Though deliberate and deniable, they’re intended to avert escalation
whilst still achieving strategic effects. Attribution is difficult,
deterrence even harder, and episodic monitoring is no longer enough.
Protecting CUI now requires persistent, high-resolution, and
cost-effective underwater surveillance on a continuous basis.
Why Traditional
Surveillance Models Fall Short
Established approaches to subsea monitoring struggle to meet this
requirement. Fixed seabed systems, such as hydrophone arrays, provide
persistent monitoring but only at known locations. Once identified, they
can be avoided, spoofed, or neutralised. Their static nature is both an
advantage and a limitation.
Crewed vessels deliver mobility, but at a prohibitive cost. Daily
operating expenses routinely exceed tens or hundreds of thousands of
dollars. Their acoustic and visual signatures are unmistakable, making
discreet monitoring impossible. Most critically, launching and
recovering underwater systems in real sea states exposes crews and
equipment to considerable risk.
Standalone AUV operations solve some problems, but cause another:
endurance. Battery limitations typically restrict missions to less than
24 hours. When depleted, the AUV must be recovered, recharged, and
redeployed. The result is a stop-start surveillance model, punctuated by
gaps precisely when persistence matters most.
In short, today’s tools were never designed for continuous, wide-area
CUI protection.
The
Shift: USVs as Motherships, AUVs as Persistent Sensors
A new operational model is emerging that fundamentally changes how
subsea infrastructure can be protected.
At its core is a symbiotic USV–AUV concept: Unmanned Surface Vehicles
acting as autonomous motherships, supporting and sustaining fleets of
Autonomous Underwater Vehicles.
This does not concern replacing ships with drones. It is about
breaking the endurance barrier and creating a system where at least one
AUV is always in the water – surveying, mapping, and monitoring critical
infrastructure – while others recharge, upload data, or stand by.
Persistence becomes the standard, not the exception.
The
Operational Principle: Continuous AUV Rotation
The model is simple yet operationally effective. A USV deploys a
fully charged AUV to survey a defined CUI corridor. As that AUV
approaches its battery or mission limit, it autonomously returns to the
USV. A launch-and-recovery system (LARS) enables safe, automated
docking, often without the AUV even leaving the water. While the
returning vehicle recharges and offloads data, a second AUV is deployed
immediately.
The result is a continuous rotation cycle: 1 – one AUV surveying; 2 –
one AUV charging; 3 – one AUV processing or standing by. There are no
surveillance gaps, no need for crewed recovery, and no dependence on
weather windows to dictate operational tempo. This capability
establishes the USV as an effective force-multiplying mothership.
The most critical function of the USV in this architecture is launch
and recovery, rather than navigation or endurance. A multi-AUV LARS
transforms the USV from a basic platform into an autonomous subsea
operations hub. It enables safe handling of multiple AUVs in real sea
states; in-water docking for charging and data transfer; and elimination
of deck-based recovery, the riskiest phase of any subsea mission.
Removing personnel from launch and recovery operations significantly
increases safety. Meanwhile keeping AUVs submerged during servicing
further increases operational uptime. In this case persistence is no
longer limited by weather, daylight, or crew availability.
AUVs: High-Resolution
Eyes on the Seabed
In this model, the AUV serves as the primary sensor platform,
operating directly where CUI is located. Medium-class AUVs offer an
optimal balance of payload capacity, endurance, and autonomy for
monitoring infrastructure. Equipped with high-resolution sonar, such as
Synthetic Aperture Sonar (SAS), they deliver centimeter-scale imagery
across wide areas of the seabed. This level of resolution is essential,
not optional.
It enables detection of subtle seabed disturbances, newly introduced
objects, cable exposure, or burial changes, and provides evidence of
tampering or pre-positioned devices. Importantly, it also enables
repeatable and comparable surveys, supporting accurate pattern-of-life
analysis along critical routes.
From Seabed to
Shore: Turning Data into Decisions
Persistence alone is insufficient; data must be transferred securely
and efficiently. In the USV–AUV model, data flows seamlessly: 1 – raw
sonar data is collected by the AUV; 2 – data is transferred during
docking to the USV; 3 – data is then pre-processed onboard to flag
anomalies and reduce bandwidth; 4 – pre-processed data is transmitted
via encrypted satellite links to shore-based command centres.
The USV acts as a mobile data gateway, providing near-real-time
intelligence to national or alliance-level command systems. Once
integrated into a wider Maritime Domain Awareness framework, this
continuous data stream enables a shift from reactive response to
proactive infrastructure defense.
Strategic
Advantages That Redefine the Mission
The benefits of this symbiotic model are transformational, not
incremental.
Persistence at Scale: Weeks or months of uninterrupted monitoring
replace short, disconnected missions; Reduced Risk: No crews are exposed
to hazardous launch and recovery operations; Operational Discretion:
Low-profile USVs and submerged AUVs significantly reduce detectability;
Economic Viability: Replacing crewed support vessels with autonomous
motherships makes persistent surveillance financially viable;
Scalability: Multiple USV–AUV teams can be deployed simultaneously
throughout vast infrastructure networks.
Together, these advantages make unmanned systems a significant force
multiplier for CUI protection.
A New Doctrine for
Underwater Security
The protection of Critical Underwater Infrastructure is no longer a
niche technical problem, it’s a strategic requirement. The USV–AUV
mothership model offers a forward-looking doctrine – one designed for
endurance, ambiguity, and scale. By making sure that there is always an
AUV in the water, it delivers the persistence required to deter, detect,
and document hostile activity in the subsea domain.
"Always One AUV in the water (Thomas Meurling – Photoshop and Nano Banana Pro)
While this model is highly relevant for CUI, its implications reach
further to mine countermeasures, ISR, and long-term seabed monitoring.
At a time when underwater infrastructure has become both a target and a
strategic lever, adopting persistent, unmanned, and integrated
surveillance architectures is no longer optional. It’s the new baseline
for maritime security.
Call-To-Action
Please comment so we all can learn from each other.
