Category: Strategic Pings

Shallow water is where submarines go to be clever… and where sonar engineers go to lose sleep.

Acoustics may be complicated in the open blue ocean, but at least the physics behaves predictably. In the littorals, Baltic-style basins, archipelagos, straits, coastal shelves, sound bounces off everything like a pinball machine with commitment issues: surface, bottom, rocks, wrecks, thermoclines that appear and disappear, and enough reverberation to make a choir sound like static.

Add dense traffic, biologics doing an interpretive dance on your spectrogram, and a seabed that changes from mud to cobble to granite in one coffee break… and you get the reality of littoral ASW.

I was fortunate to receive training from Professor Urick, who compared the Baltic with a portion of the South China Sea with respect to the hydroacoustic environment. Very complicated, he made one comment, “Avoid it if possible…”

Which is exactly why the strategic stakes are rising. Coastal waters aren’t just “nearby.” They’re gateways: ports, sea lines, chokepoints, and the corridors where critical infrastructure lives. If an adversary submarine can operate in your backyard, it’s not only hunting ships. It’s mapping patterns of life, sniffing undersea cables, and quietly rewriting your risk calculus. ASW in littoral and shallow coastal water relates to seabed warfare.

Here’s the uncomfortable truth: in littoral ASW, you have two valid ways to win.

You find the submarine.

You create deterrence, A2/AD, so submarines don’t dare to loiter in your operating box in the first place.

Those are not competing ideas. They’re a matched pair.

The Deterrence Frame: ASW as A2/AD, not just “search and maybe prosecute.”

A2/AD—Anti-Access / Area Denial, is the maritime equivalent of putting a “Keep Out” sign on the sea and then wiring the fence to the national grid.

Anti-Access (A2) is about stopping an opponent from getting into the fight. In ASW terms, that means controlling the gateways: straits, archipelagos, shelf breaks, and the transit routes submarines and their supporting forces depend on. If you can threaten the aircraft, ships, bases, and logistics that enable sustained ASW, you can keep the hunter outside the operating box—no presence, no search pattern, no persistence.

Area Denial (AD) assumes the opponent makes it in anyway and focuses on making operations slow, risky, and inefficient. This is where ASW becomes a layered trap: seabed sensors, USVs towing passive arrays, UUV patrols, mines, decoys, jamming, spoofing, and enough ambiguity in the acoustic environment to keep commanders awake. The goal is not always a dramatic kill. Often it is simpler: deny tempo, deny confidence, deny freedom of maneuver.

A2 keeps the door closed. AD turns the room into a maze of tripwires.

Now—where does multi-static USV ASW fit? Right in the sweet spot: it supports both. It can actively find submarines, and it can also help create the perception (and reality) that your shallow-water approaches are simply not comfortable to operate in.

That discomfort is deterrence.

The submarine’s favorite shallow-water playing card: Zero Doppler

Submarines don’t need to be truly invisible. They need to be hard to classify and hard to hold. In shallow water, the ocean gives them plenty of cover: boundary reverberation, multipath, shipping noise, biologics, and bottom clutter.

One of the most useful tactical tricks is Zero Doppler geometry.

If the submarine can maneuver so that its radial velocity relative to your active sonar geometry is near zero, Doppler cues get weak. Your discrimination suffers. Your tracker gets less confident. Your contact starts looking like “maybe something,” which is operationally deadly because “maybe” burns time—and in the littorals, time is what the submarine is stealing.

If Zero Doppler provides a strategic edge, the key question is: how can we remove that advantage?

The Multi-static answer: Geometry that the submarine can’t game

Monostatic active sonar (source and receiver on the same platform) is vulnerable to geometry games. A multi-static network is not.

In multi-static operations, you separate the source from multiple receivers distributed in space. A submarine can try to be zero Doppler to one receiver, but it cannot maintain zero Doppler to several receivers spread across different bearings and ranges at the same time. If it’s “boring” to one node, it will be moving relative to another. That means Doppler diversity returns to your side of the chessboard.

This isn’t a small technical upgrade. It’s a strategic shift: you deny the submarine control of the engagement geometry.

And that denial is exactly what AD is supposed to feel like.

The Multi-Static USV Swarm: One illuminator, many ears (and no single point of failure)

The clean basic CONOPS is a “1+4” USV formation:

1) Source USV (the illuminator)

One USV carries a high-power coherent source, typically 2–4 kHz for wide-area search in shallow basins. Coherent matters because the littorals punish lazy waveforms. You want control: multiple pings, variable durations, better processing gain, and the ability to adapt to a reverberation floor that changes by the hour.

Think controlled flashlight, not fireworks.

3–4 Receiver USVs (the listeners)

Three to four USVs tow passive towed arrays—digital, high dynamic range systems designed to capture high-fidelity snippets for fusion. These nodes stay acoustically passive, which helps survivability and reduces self-noise issues, while providing the geometry diversity that makes multi-static worth doing.

This architecture is also inherently resilient. Lose one node? The web degrades gracefully rather than going blind. That matters in contested littorals where attrition is not a hypothetical—it’s a planning assumption.

Shallow-water reality check: timing, navigation, and “ghost discipline”

Multi-static processing is unforgiving. If your timing is sloppy or your positions drift, you don’t get “slightly worse tracks.” You get false tracks. Ghosts. Expensive arguments.

This is why serious multi-static USV ASW needs:

• Tight clock discipline (microsecond-level timing),
• High-quality navigation fusion (INS + DVL + pressure, plus sanity checks), and
• Geometry control so your bi-static ellipses actually mean something.

Your system must keep behaving even when you have issues, because the submarine will not politely pause while you reboot your confidence.

Search Patterns: Don’t “swarm,” orchestrate

A swarm is a marketing word. Formation is an engineering word.

Receiver USVs should execute structured search patterns designed to maintain baseline spacing, angle diversity, and revisit rates that support tracking. A practical approach is coordinated “lawnmower” sweeps with controlled offsets, where:

• The source illuminates on a schedule,
• Receivers maintain geometry to maximize bistatic angle diversity,
• Network adapts spacing based on propagation and bathymetry.

The goal isn’t just detection. It’s hold. Hold is what enables deterrence, because a submarine that expects to be held behaves differently than a submarine that expects to slip away.

How this feeds A2/AD: Deterrence by Transparency

Here’s the strategic payoff:

A distributed multi-static USV field doesn’t just hunt submarines. It creates a perception—backed by physics—that your littoral approaches are becoming transparent.

That supports A2 by controlling gateways. Place these fields intelligently near straits, archipelagos, and shelf breaks, and you complicate transit planning. You force route deviations, slower speeds, and higher risk. You also threaten the supporting ecosystem, tenders, ISR assets, surface escorts, that submarines rely on for sustained operations.

And it supports AD by turning the operating area into a maze of tripwires. Even if the submarine enters, it cannot rely on its best stealth geometry. It cannot assume it can “go zero Doppler and disappear into clutter.” The web denies tempo and denies confidence—and a commander who lacks confidence becomes conservative.

That is deterrence in practice: not always a kill chain, often a decision chain.

Summary: Two ways to win, one architecture that supports both

Littoral ASW is not a single game. It’s two:

Find the submarine when it enters your operating box.

Prevent submarines from operating there comfortably through A2/AD deterrence.

A multi-static USV architecture, one coherent source USV and 3–4 receiver USVs towing passive arrays, supports both missions. It handles the shallow-water physics with spatial diversity, resilient geometry, and edge processing. And it delivers the strategic punch: it removes the submarine’s zero-Doppler playing card by forcing it to face multiple receivers at once.

A2 keeps the door closed. AD turns the room into a maze of tripwires. Multi-static USV ASW does something even better: it makes the submarine wonder if the room was ever safe to enter at all.

Call-To-Action

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Originally published in the Strategic Pings ))) newsletter on LinkedIn on 2026-02-17. Subscribe there to get new editions first.

GNSS jamming, spoofing, and the hard lessons from NATO exercises

During a NATO Task Force exercise in 2025, I watched a USV quietly lose its mind.

On the screen, our unmanned surface vehicle was suddenly “turn starboard 90 degrees and doing 50 knots” sideways. The track jumped inland. Position fixes wandered like a drunk reindeer in the archipelago. The hardware was fine. The environment was not.

We were sitting inside a live GNSS jamming and spoofing bubble.

For a manned ship, this is annoying but manageable. A human on the bridge says “this is garbage”, switches to radar, visual bearings and paper charts, and carries on. For an unmanned system, there is no salty navigator to shout at the GPS.

If your USV believes bad PNT, it does bad things.

That is the real problem.

The fragile keel: USVs built on weak PNT

Modern USVs are deeply GNSS-centric. Position, timing, comms pointing, collision avoidance, and route following. Much of it assumes that satellite navigation is “good enough, most of the time”.

In a real-world contested environment, that assumption quickly dies. Luckily, there was a skilled engineer (whose last name I cannot mention, as it is bad luck) who had the solution.

• Jamming makes you blind
• Spoofing makes you confidently wrong

For critical missions around naval exercises, offshore energy, or subsea infrastructure, that is not a nuisance. It is an operational risk.

And unlike a crewed vessel, the USV will happily:

• Track to a spoofed waypoint
• Violate a safety box
• Misalign a towed sensor
• Lose alignment with its AUV swarm

Simply because the math checked out on a compromised GNSS stream.

Navigating in the dark: sensor fusion or nothing

The path out of this trap is not a magical “GPS replacement”. It is ruthless redundancy.

For USVs, that means building a resilient PNT stack, not just “adding an INS”.

At minimum:

• Good IMU + INS for dead reckoning
• DVL or water-track speed, where the draft allows it
• Radar and EO/IR for shoreline, buoys, and traffic
• Multi-constellation + authenticated GNSS where available

With decent inertial quality and a DVL locked on the seabed, drift over tens of minutes becomes manageable. Sensor fusion algorithms can then do what they do best. They compare “what GNSS says” with “what the rest of physics says”.

If your Kalman filter sees a perfect satellite position disagreeing with inertial, DVL, and radar ranges, it does not need a PhD in electronic warfare. It just needs to vote GNSS off the island.

The key is architectural: Treat GNSS as one sensor among many, not the truth.

Design for failure: behavior when PNT goes bad

Resilient PNT is not only about sensors. It is also about what the USV does when things get weird.

For unmanned systems, I like to see three explicit modes:

• PNT Healthy — Normal operation. GNSS + fusion. All constraints green.
• PNT Degraded — GNSS flagged as suspect or lost. USV shifts to INS / DVL primary. Speed limits come down. Safety corridors widen. Autonomy level drops.
• PNT Lost / Corrupted — Pre-defined “lost nav” behavior. Slow to safe speed, hold last safe box using non-GNSS sensors, or return along a radar-matched corridor. No heroic improvisation.

These modes must be tested in anger. In a jammer. In a harbor full of multipath. In a fjord with poor DVL lock. If your USV only behaves well under perfect GNSS, it is not autonomous. It is domesticated.

From convenience to survivability

GNSS gave us a very comfortable decade. Cheap antennas. Easy integration. Pretty tracks. For manned shipping it will remain an amazing convenience.

For USVs operating near conflict zones, hybrid warfare, or critical underwater infrastructure, GNSS is no longer a convenience issue. It is a survivability issue.

The takeaway from this exercise was simple:

• The threat is real.
• The tech to handle it exists.
• The gap is in system design and in testing.

If your unmanned platform strategy does not include:

• A serious, fused PNT architecture
• Defined degraded-mode behaviors
• Regular exposure to jamming and spoofing environments

Then your shiny USV is only autonomous as long as nobody touches the satellites.

Strategic Ping: Do not ask “what GNSS do we have on the USV?” Ask “what happens when it lies?”

Call-To-Action

Please comment, repost, and discuss this important issue. I’m not a specialist in this, but I learned from colleagues who are experts.

We need to learn from each other and create best practices.

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Originally published in the Strategic Pings ))) newsletter on LinkedIn on 2026-02-10. Subscribe there to get new editions first.

1. The Underwater Perimeter Has Moved

The waterline is no longer the boundary of maritime security. That line has sunk below the surface, into a domain that is opaque, cluttered, and unforgiving of delay.

Ports, naval bases, offshore energy assets, pipelines, and subsea infrastructure are now threatened primarily from below. Dive Detection Systems (DDS) have therefore become foundational elements of maritime protection architectures.

Yet despite significant advances in sonar performance, classification algorithms, and autonomy, most underwater security failures still stem from the same root cause:

Reaction time.

Detection alone does not stop an intrusion. Detection without timely action merely records it.

2. The Threat Has Changed Faster Than the Response Model

Historically, the underwater threat was human and constrained. Open-circuit divers produced bubble trails. Endurance was limited. Approaches were slow and predictable.

That era is over.

Today’s threat landscape includes:

• Closed-circuit rebreather divers with no visible bubble signature
• Widely available high-end commercial dive equipment
• Unmanned Underwater Vehicles (UUVs) with long endurance and zero risk to the operator

Complicating matters further, ambiguity is now routine. A sonar contact may be a saboteur, a recreational diver, or a survey drone. The sensor does not know. The command chain must decide.

And every second spent deciding compresses the remaining response window.

3. Detection Is a Solved Problem. Reaction Is Not.

Modern DDS sensors can detect small, slow targets in noisy, cluttered environments. The technical challenge of “seeing” underwater has largely been addressed, even if there are still issues with “false alarms”.

The operational challenge has not.

A credible dive detection architecture must support the full chain:

• Early detection
• Rapid classification
• Low-latency alerting
• Immediate, actionable response

If any part of that chain relies on slow human mobilization, the system fails operationally — even if it performs perfectly on paper.

4. Key Detection Systems and Their Strategic Roles

Forcys Sentinel

Forcys Sentinel is designed for long-range early warning. Its strength lies in coverage and standoff distance, detecting divers at significant ranges and UUVs even farther. There is also an interesting passive mode.

Strategically, Forcys Sentinel buys time. That time is critical for cueing mobile assets and initiating autonomous response actions before the intruder reaches the asset of interest. Sentinel performs best as the outer layer in a layered defense architecture.

DSIT AquaShield

AquaShield focuses on autonomy and discrimination. Advanced signal processing and adaptive thresholding reduce false alarms in busy harbors, which is operationally vital.

False alarms consume attention, degrade trust, and slow reaction. By delivering higher-confidence alerts, AquaShield accelerates decision-making and supports rapid escalation when required. Its hardened design also reflects an assumption that sensors themselves may be targeted.

SDIT also has the PointShield, a smaller portable sonar system.

Norbit GuardPoint

GuardPoint systems are optimized for persistent, fixed monitoring of critical infrastructure. Their value lies in continuous availability and reliability in known geometries such as ports and terminals.

As with all fixed systems, GuardPoint’s effectiveness depends on how quickly a response asset can be cued and dispatched. Integrated properly, it becomes a reliable sentry rather than a passive observer.

Norbit has several different sonar systems for intruder detection, all of which are named GuardPoint.

5. Why Human-Centric Response Fails

The moment an intruder is detected, the clock starts.

Traditional response concepts assume:

• An operator raises an alarm
• Personnel are notified and mobilized
• A patrol boat is crewed, started, and deployed
• The boat transits to the contact location

This sequence may take 20 to 60 minutes — sometimes longer.

For underwater intrusions, that is an eternity.

By the time a crewed vessel reaches the scene, the diver has exited, the UUV has completed its task, and the opportunity to act is gone.

This is why humans cannot be the first responders.

6. Automating the Response Loop

The only viable response model is a machine-speed reaction layer, centered on unmanned surface vehicles (USVs).

In this architecture, humans remain in command — but not in the pursuit loop.

The Operational Flow

Detection — A fixed or mobile DDS detects and tracks a subsurface contact.

Immediate Autonomous Dispatch — A pre-positioned USV is activated instantly. No crew. No delay.

Re-Detection and Close Classification — The USV intercepts the target and re-detects it using high-resolution, motion-stabilized sonar, maintaining continuous track despite sea state and maneuvering.

Evidence, Not Assumptions — The USV transmits sonar imagery, tracks, and behavioral data to the Commanding Officer via secure data link.

Command Decision at the Right Level — The CO receives verified classification, not raw alarms, and authorizes action while the intruder is still present.

This model preserves command authority while eliminating fatal latency.

7. Neutralization Options: Speed with Control

Once classification is confirmed, response options must already be integrated with the USV.

Typical actions include:

Physical Capture — Net systems launched from the USV to entangle divers or disable UUV propulsion. Clean, non-lethal, and legally straightforward.

Acoustic Disruption — Directional acoustic devices, including airgun-based systems, that create localized shock, vibration, or disorientation to deny mission completion.

Critically, these actions are executed from the unmanned platform, not after human arrival. The CO authorizes. The system acts.

8. The Strategic Takeaway

Dive detection is no longer a sonar problem. It is a time management problem.

The systems that matter are not those with the longest range or smallest detectable target, but those that compress the timeline from first acoustic return to decisive action.

If your response depends on waking people up, starting engines, and driving to the scene, you are already too late.

Underwater security is won by closing the loop, autonomously, quickly, and with command authority applied at the right moment.

In the subsea domain, reaction time is the weapon. Everything else is instrumentation.

Call-To-Action

Please provide comments and challenge me. We all need to discuss to learn more from each other.

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Originally published in the Strategic Pings ))) newsletter on LinkedIn on 2026-02-02. Subscribe there to get new editions first.

Introduction: The Sensor That Saves You Before You Realize You Needed Saving

Everyone loves the glamorous sensors on a USV. Radar provides long-range detection capabilities. Lidar with Hollywood laser precision. Cameras that could film a documentary about seagulls. Multibeam sonar maps the seafloor with centimeter-level resolution.

And then there is the Forward-Looking Sonar (FLS). Quiet. Underrated. Sitting low below the bow like a hardworking intern who prevents the company from collapsing every Friday afternoon.

It may not get the marketing spotlight. But it is the one sensor that keeps the USV from becoming a very expensive hood ornament on a hidden rock.

Let us talk about why.

The Blind Spot That Refuses To Go Away

USVs now operate in places where charts are unreliable. Many are old. Some are missing data. Some are works of fiction.

Downward echo sounders only report where you already were. Surface sensors cannot see below the waterline. Autonomous systems require accurate, real-time data to operate effectively.

This creates a single dangerous gap:

The underwater domain directly ahead of the bow.

That is where you find:

• Uncharted hazards
• Rocky pinnacles
• Coral heads
• Submerged debris
• Hidden ice
• Containers drifting just below the surface

Without forward-looking sonar, the USV is effectively blind underwater. Not ideal when you want the platform to survive the mission.

I’ve seen several times USVs crashing into underwater obstacles, the latest at Taskforce X in Finland, when one USV crashed so hard that it almost sank.

Why Forward-Looking Sonar Matters

2D forward-looking sonar can detect objects ahead, but does not provide depth information. The result is often ambiguous, making it difficult to assess the situation.

Operators or autonomous systems cannot determine whether the object is:

• Deep and safe
• Or shallow and destructive

Modern forward-looking sonar, including 3D models, provides a comprehensive underwater view with range, bearing, and depth information. This transforms sonar data into actionable insights.

This enables confident and reliable navigation.

Application 1: Real Obstacle Avoidance Below the Surface

Forward-looking sonar complements the other sensors, such as radar, cameras, and Lidar, which monitor the surface. Together, they provide comprehensive situational awareness.

FLS detects:

• Reefs and shoals
• Coral formation
• Ice features
• Marine mammals
• Lost shipping containers
• Old infrastructure
• Rapid seabed changes

This information feeds directly into the autonomy engine. The USV reacts in real time. It adjusts course. It avoids the hazard. It enables the USV to complete its mission efficiently and safely.

This capability is essential for mission assurance.

Application 2: Tactical Survey and Rapid Environmental Assessment

Forward-looking sonar (FLS) is not designed for detailed hydrography like multibeam systems. Its primary strengths are speed and situational awareness.

When seabed conditions change unexpectedly, FLS provides the fastest means to obtain an updated underwater view.

It supports operations such as:

• Natural disaster response
• Rapid environmental assessment
• Safe passage planning after storms
• Quick checks before sending in AUVs or divers

The USV gathers usable data on the move. Operators immediately see what changed. Survey teams know where to focus the high-resolution MBES lines.

This shortens timelines. Reduces uncertainty. It also eliminates unnecessary survey routes.

This enables tactical surveys to be conducted at operational speed.

Application 3: An Essential Enabler for Mine Countermeasures (MCM)

Mine countermeasures is a field where “do not hit anything” becomes an official strategy.

Forward-looking sonar supports MCM operations by:

• Revealing underwater structures near the USV
• Showing rapid bathymetric changes
• Helping maintain stand-off from threats
• Protecting the platform during maneuvers

The MCM payload may do the heavy classification work. However, FLS ensures the USV remains operational long enough to deploy these systems.

It serves as a critical safety layer, preventing the USV from triggering mines.

Application 4: Daily Navigation in Unpredictable Waters

Ports change. Rivers shift. Tropical channels grow new sandbars every week. Ice forms underwater ledges that can break a hull. Offshore wind farms hide half-built subsea structures.

Forward-looking sonar gives immediate underwater awareness in these dynamic environments.

It helps the USV:

• Detect changes since the last mission
• Navigate near infrastructure
• Avoid submerged work platforms
• Stay safe in shallow and shifting waters

Routine navigation becomes more effective. It is also more predictable. And far safer for an unmanned asset.

Example of Systems

The graph below shows an example of forward-looking sonar systems.

Norbit FLS Sonar: A compact and advanced forward-looking 2D sonar. I see this as the baseline FLS and fulfill 80% of all requirements for any USV. It is easy to install and operate, and can function as a dual-head with the Norbit MBES series, offering significant integration advantages in smaller USVs for hydrographic applications.

Farsounder Argos 3D Sonar: This system provides 3D mapping capabilities and can be integrated into various bridge systems. The system can also interface to QPS software.

Wavefront 3D Sonar: This high-end 3D sonar offers higher resolution and improved performance, though it is significantly more expensive.

Conclusion: The Three Things That Matter Most

If you take away three key points, they are:

The underwater blind spot is the most dangerous threat to a USV. Charts and surface sensors cannot fix it.

Forward-looking sonar is the only sensor that gives real-time underwater awareness. It closes the one gap that autonomy cannot guess through.

It enables critical applications such as obstacle avoidance, tactical surveys, rapid environmental assessment, safer mine countermeasures, and improved navigation in challenging waters.

Forward-looking sonar may never get the glamour slots at conferences. But it is the sensor that prevents the headlines nobody wants.

This is why Forward-Looking Sonar is nonnegotiable for USV operations

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Please comment and provide feedback so we all can learn from each other

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Originally published in the Strategic Pings ))) newsletter on LinkedIn on 2026-01-27. Subscribe there to get new editions first.

Unmanned Surface Vehicles (USVs) are well established in hydrography and mine countermeasures. However, their most significant impact is now emerging in Intelligence, Surveillance, Reconnaissance (ISR) and Anti-Submarine Warfare (ASW).

I’m a strong believer in integrated ISR with Passive ASW, and as a former submariner (bubblehead), I believe they complement each other.

These missions involve challenging detection, strict timelines, and strategic consequences for errors. In this context, one principle remains:

A USV is not the capability. A USV enables the capability.

The true value lies in the payload, sensor integration, and the ability to convert raw data into actionable intelligence.

ISR Is No Longer About Sensors. It’s About Understanding.

Modern ISR-configured USVs serve as autonomous watchstanders. They operate continuously and do not miss radar sweeps.

The sensor suites are familiar: maritime surveillance radar, long-range EO/IR, AIS, electromagnetic sensors, and increasingly, passive acoustics. None of these are revolutionary on their own.

The transformation comes from how these sensors are integrated.

Radar establishes presence at range. EO/IR confirms identity. AIS either validates intent or exposes deception. EM sensors reveal electronic behavior invisible to the eye. Autonomy engines analyze patterns, correlate domains, and predict behavior.

Operators no longer monitor disconnected feeds; instead, they receive a coherent maritime picture.

This distinction is important. In gray-zone environments, where ambiguity is used as a tactic, early recognition of intent is often more decisive than firepower.

The modern EW and SIGINT landscape is being shaped by the strategic convergence of several interdependent technological trends. The integration of Artificial Intelligence (AI) and machine learning onto unmanned platforms—across air, sea, and land domains—is enabling autonomous sensor grids to operate at the tactical edge without constant human oversight.

These distributed networks of assets extend the reconnaissance horizon and reduce risk to personnel by removing the human operator from the immediate tactical environment. Concurrently, an industry-wide shift toward modular, open-architecture systems is the critical enabler for this evolution. This “future-friendly” design philosophy allows for the rapid integration of new AI algorithms and diverse sensor payloads onto unmanned platforms, ensuring that forces can adapt faster than their adversaries. Together, these trends are creating a more distributed, resilient, and lethal force, capable of processing vast amounts of intelligence data at machine speed to accelerate decision-making and stay ahead of emerging threats.

Prominent manufacturers are Northrup-Grumman, HENSOLDT, Rafael, L3Harris, and Teledyne.

ASW: Where USVs Deliver Disproportionate Advantage

While ISR is complex, ASW is even more demanding. It remains the most challenging mission in maritime warfare and is increasingly costly to sustain with only manned platforms.

Traditional ASW relies on frigates, maritime patrol aircraft, and helicopters. While these platforms are highly capable, they are limited by cost, crew requirements, and endurance.

USVs change this dynamic.

A well-designed USV can tow a passive array at four to six knots for extended periods, operating quietly and persistently without risking personnel. With modern onboard acoustic processing, including broadband, LOFAR, DEMON, and environmental modelling, even medium-sized USVs can detect, classify, and track targets.

This capability is operational, not experimental, and provides significant leverage.

Ultra-low radiated noise makes USVs effective passive sensors. Their long endurance allows for continuous patrols. Low-probability-of-intercept communications maintain stealth, while autonomous behaviors ensure contact geometry and track continuity.

When deployed in numbers, USVs form mobile acoustic pickets, extending ASW coverage well beyond the limits of manned forces.

Passive Towed Arrays, utilized by both submarines and surface combatants, are substantial in length, up to 150-2000 meters aperture, which require larger winch systems, not feasible on medium-sized USVs.

For USVs, the typical aperture length will be 25–150 meters, due to the size and weight of winch equipment.

Prominent manufacturers are L3Harris, THALES, ATLAS, SEA, Sensor Technologies, Raytheon, and Kongsberg

Integration Is the Capability

As with hydrography and mine warfare, the hull itself is secondary. In ISR and ASW, integration is everything.

Precision navigation and motion reference underpin acoustic performance.

Secure, resilient communications, LOS, SATCOM, mesh, move intelligence where it matters.

Edge computing enables real-time processing, reducing latency and bandwidth demand.

Autonomy manages execution: patrol adaptation, contact following, dynamic re-tasking. Humans remain firmly in the loop, supervising intent and authorizing decisions—but they are no longer burdened by mechanical control.

This is why leading USVs should not be viewed as “remote boats.” They are autonomous intelligence nodes, designed to operate as part of a wider maritime sensing architecture.

How These Systems Are Being Used Today

Globally, ISR USVs conduct persistent patrols along EEZ boundaries, monitor smuggling routes, and identify dark shipping by fusing AIS, radar, and EO/IR data.

Ports and coastal authorities use USVs to track small craft, monitor choke points, and correlate surface activity with acoustic and electromagnetic signatures.

In ASW, multiple USVs with towed arrays are deployed as acoustic barriers, coordinated with AUVs and sonobuoys in multi-static configurations. Contacts are continuously maintained and transferred to manned assets as needed.

For covert ISR, low-signature USVs conduct discreet patrols, collect imagery, and passively monitor RF and EM activity without revealing their presence.

No crewed vessel can match this combination of persistence, discretion, and cost efficiency.

The Strategic Shift: From Missions to Presence

ISR and ASW are shifting from platform-centric activities to distributed, networked sensing challenges.

USVs are well suited to this model. They offer persistent presence, stealthy acoustic profiles, real-time data fusion, and, importantly, scalability.

They enable navies to transition from episodic deployments to continuous operations.

This is the true strategic advantage.

Final Thought

USVs are not replacing frigates, maritime patrol aircraft, or submarines. Instead, they enhance these platforms by extending sensor reach, persistence, and situational awareness across the battlespace.

A USV without integrated sensors is simply a boat. A USV equipped with radar, EO/IR, AIS, electromagnetic sensors, and a passive towed array becomes a valuable ISR and ASW asset.

The direction is clear.

The future of maritime security will be unmanned, integrated, networked, and persistent, with USVs at the center of this transformation.

Call-To-Action

Please comment and provide your ideas, so we can learn from each other.

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Originally published in the Strategic Pings ))) newsletter on LinkedIn on 2026-01-20. Subscribe there to get new editions first.

After being in the sonar design business for over 30 years, there are not many things that get me excited. But this Nano76 is an exception, I got really excited when I was reading about this development. I couldn’t find much, so I decided to collect all available information and present it in one of my Newsletters. This is based on open public information, so it may not be 100% correct.

Big shifts in naval warfare rarely arrive with fanfare. They arrive quietly. Smaller. Lighter. Smarter.

And then, a few years later, everyone wonders how they ever operated without them.

Thales’ recent unveiling of the Sonar 76Nano belongs squarely in that category.

At first glance, it looks like a classic case of miniaturization. In reality, it is something far more disruptive.

It is a strategic payload designed for a world where seabed warfare, autonomous systems, and persistent underwater surveillance are no longer optional.

They are the baseline.

From Flagships to Tiles

The Sonar 76Nano is not an incremental upgrade. It is a philosophical shift.

Thales has taken the DNA of its flagship Sonar 2076, the system that sits at the heart of the Royal Navy’s most capable submarines, and compressed it into modular tiles measuring roughly 75 by 75 centimeters.

This development is significant.

When high-end sonar is no longer limited to nuclear submarines and large frigates, the balance of power beneath the sea shifts fundamentally.

Advanced acoustic sensing is no longer limited to:

• Billion-dollar platforms
• Limited fleet numbers
• Crewed assets with political risk attached

Instead, it can be deployed on UUVs, seabed nodes, and autonomous systems designed for quiet, long-term operation.

That is the real breakthrough.

Why This Happened So Fast

This prototype did not take a decade. It took ten months.

Thales invested over £2 million of its own funding to make it happen. That alone tells you something important.

This was not a technology-push project. It was a strategic response.

The subsurface domain is heating up. Fast.

Russian submarine activity around the UK has increased sharply. Chinese survey vessels are mapping seabeds across the Indian Ocean. Undersea cables and pipelines are no longer abstract infrastructure. They are targets.

At the same time, Western navies are operating fewer hulls. Fewer submarines. Fewer frigates.

But the ocean did not get any smaller.

That gap between demand and force structure is exactly where autonomous systems move from “interesting” to “essential”.

Autonomy Needs Real Sensors

There is an uncomfortable truth about autonomous platforms.

Autonomy without sensing is just expensive drift.

What makes the Sonar 76Nano important is not that it is autonomous-friendly. It is that it brings real acoustic capability to platforms that previously carried compromise sensors.

Active and passive modes matter here.

In passive mode, a UUV becomes a quiet listener. Persistent. Patient. Hard to detect.

In active mode, with low-probability-of-intercept signaling, it becomes something more interesting.

A node.

Not just a sensor, but part of a submerged network.

This is how underwater mesh networks start to look operational rather than academic. Vehicles that detect, classify, share, and cue without surfacing or calling home every five minutes.

That is a very different game.

Seabed Warfare Is No Longer Theoretical

For years, seabed warfare lived mostly in conference slides. That phase is over.

Cables have been cut. Pipelines have been sabotaged. Survey vessels are no longer assumed to be benign.

The Sonar 76Nano is clearly designed with this reality in mind.

Its integrated synthetic aperture sonar provides long-range, high-resolution seabed imaging that does not degrade with distance. That is exactly what you want when inspecting cables, pipelines, or suspicious seabed activity at speed.

More importantly, it enables persistence.

A UUV does not need a crew rotation. A seabed node does not need coffee.

It just listens. And watches.

The Real Power Is the Network

No modern sonar operates alone. And the 76Nano is very much a digital-native system.

Designed from the outset to plug into UK and NATO architectures, it feeds into a larger picture rather than creating yet another stovepipe.

That matters operationally.

Data from autonomous platforms only becomes strategic when it fuses with:

• Towed arrays
• Dipping sonars
• Fixed seabed sensors
• Intelligence feeds

This is how navies move from individual detections to what commanders actually want. A recognized persisitant underwater picture.

Or, put more bluntly. Who is down there. Where. And what they are doing.

Three Strategic Takeaways

If you zoom out, the Sonar 76Nano points to three very clear shifts.

First: High-end ASW is no longer exclusive Miniaturized, high-performance sonar breaks the monopoly of large, crewed platforms. That changes deterrence math. For everyone.

Second: The hybrid fleet is now unavoidable Crewed platforms orchestrating autonomous sensors is no longer a concept. It is becoming doctrine.

Third: Seabed security moves from reactive to persistent You cannot protect what you only inspect after something breaks. Persistent sensing changes the timeline. And the outcome.

Final Ping

The Sonar 76Nano is not just a smaller sonar.

It is a strategic enabler for how navies will think about underwater presence, risk, and control over the next decade.

Less about platforms. More about payloads. Less about episodic patrols. More about continuous awareness.

In seabed warfare, size still matters.

Just not in the way it used to…

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Originally published in the Strategic Pings ))) newsletter on LinkedIn on 2026-01-13. Subscribe there to get new editions first.