The recent convergence of three technical threads is changing how navies conceive anti-submarine warfare. First, platforms that can loiter at sea for weeks without human presence have moved from conceptual demonstrations to operational test assets. Second, distributed sensing and modular payloads now allow unmanned surface and undersea vehicles to carry the kinds of acoustic, magnetic, and active sensors that were once the exclusive province of manned ships and aircraft. Third, machine learning and edge processing are finally delivering the ability to triage, classify, and act on faint acoustic signatures in near real time. Together these developments amount to more than incremental improvement. They constitute a structural shift in the ASW problem set and in the human responsibilities that accompany it.

We should begin with the hardware baseline. Sea Hunter and its ACTUV lineage proved the value of a relatively large, unmanned surface platform able to transits long distances and operate in compliance with the rules of the sea while performing persistent missions. That demonstrator moved from DARPA into longer term development under naval stewardship, validating the concept of an autonomous sub-hunter at sea. In parallel the United States Navy accepted the first Boeing XLUUV test asset, colloquially known as Orca, a large autonomous undersea vehicle designed for monthlong, long-range missions and modular payload integration. The Orca program moved the conversation from modest endurance AUVs to true strategic reach for unmanned undersea systems.

These platform advances are not mere feats of engineering elegance. They alter the geometry of ASW. A distributed force of UUVs, USVs, and aerial systems can create spatially extensive sensor apertures. That aperture lets operators transform a classic contact-hunting problem into one of networked detection and attribution. Practically speaking this means a USV towing a passive array, an XLUUV that can lay on the seabed with a suite of hydrophones, and an unmanned aircraft that dispenses sonobuoys can collaborate to generate multilateration solutions that were previously infeasible. Industry and navies are already demonstrating individual pieces of that puzzle. For example, tests of sonobuoy dispensing from long-endurance unmanned aircraft showed successful release and monitoring procedures, broadening the range of platforms that can seed an acoustic net.

Sensing alone, however, does not solve the problem. The ocean is a fiercely noisy domain. A small diesel electric submarine in coastal waters yields a signal buried in a dynamic soundscape of shipping, biological noise, and layering effects. Here the recent literature is important because it shows practical progress in the signal processing and machine learning techniques required to lift targets from that noise. Contemporary surveys and experimental work document substantial improvements in automatic classification, noise-robust feature extraction, and end-to-end deep learning methods tailored to ship radiated noise and underwater acoustics. Those advances change the scale at which an unmanned fleet can meaningfully reduce operator workload and false alarm rates.

But the breakthrough is partially architectural. The unmanned systems revolution is not a single platform winning a new capability. It is a modular, composable approach in which autonomy is distributed across vehicles and across the maritime infrastructure. The XLUUV’s modular payload bay, autonomous navigation stack, and long endurance give planners a plug and play asset for seabed surveillance, distributed passive arrays, and communications relays. The ACTUV concept showed how a USV can trail and shadow contacts while obeying navigation law. The practical upshot is a palette of mission design options that prioritize persistent coverage, not episodic detection.

There are, inevitably, limits and caveats. Machine learning models trained on archival acoustic data may not generalize to new soundscapes or deliberate adversary deception. Edge computing reduces latency but places hard constraints on model complexity and on how training and updates are distributed. The data pipelines and classification thresholds that work in a carefully instrumented test range may perform poorly when confronted with varied bathymetry, uncertain oceanographic conditions, or adversaries who purposefully mask signatures. The naval community must therefore resist the narrative that autonomy is a turnkey panacea. Robust ASW will remain a systems problem of sensing, oceanography, doctrine, and human judgment.

The ethical and strategic questions are equally pressing. As autonomy migrates from navigation to targeting support the chain of authority becomes more opaque. Who is accountable for a classification-driven engagement decision that begins with an algorithm on a distant USV or XLUUV? The architecture we design today will embed norms about human oversight, human-in-the-loop intervention, and auditability. If history is a guide, technical affordances will tend to outpace doctrine. We must choose, deliberately, how far to let autonomy act without a human in the loop and how to structure human supervision when the tempo of detection is faster than human cognitive bandwidth.

Practically, what should naval planners and technologists prioritize? First, emphasize interoperability between unmanned platforms and legacy ASW assets. Demonstrations that combine unmanned aircraft sonobuoy dispensing, USV towed arrays, and UUV seabed listening posts are more decisive than isolated platform milestones. Second, invest in robust acoustic model transfer and continual learning frameworks so onboard classifiers degrade gracefully and can be updated with human-in-the-loop validation. Third, codify transparent decision logs and forensics for any autonomy-assisted contact classification so that commanders can reconstruct rationale after the fact.

Finally, allow room for philosophical humility. The ocean is a complex adaptive system that continually surprises even the best models. Autonomy will expand our reach and reduce risk to sailors, but it will not exempt us from responsibility. The most consequential breakthroughs in maritime ASW will be those that supplement human judgment and preserve clear lines of accountability while extending the reach of sensors and the endurance of presence. Technological progress alone will not solve the moral calculus of undersea confrontation. That calculus must be decided by institutions that can bind technology to law and to the enduring norms of naval practice.