The US Navy’s USX-1 Defiant unmanned surface vessel ( USV ) promises cost-effective, high-endurance fleet expansion while raising critical questions on survivability, cyber vulnerabilities and whether sea drones will be enough to counter China’s overwhelming shipbuilding advantage.
This month, Naval News reported that Serco, under the Defense Advanced Research Projects Agency’s ( DARPA ) No Manning Required Ship ( NOMARS ) program, launched the USX-1 Defiant, a 180-foot-long, 240-ton USV, at Nichols Brothers Boat Builders.
The unmanned vessel, coined by some media as a “ghost” ship, is designed from founding to exclude any ship features, epitomizing a groundbreaking marine infrastructure focused on price performance, stability and expanded load capabilities for long-duration missions.
Unlike fitted options like Nomad and Ranger, Defiant omits human-oriented methods. This development is crucial amid growing needs for cost-effective USVs able of countering proper risks, including a possible US conflict with China in the Taiwan Strait or South China Sea.
The vehicle features DARPA’s superior hydrodynamic and secrecy technologies. It aims to maintain 90 % administrative stability over a year, and its autonomous fuel functions have been demonstrated in previous tests.
This project aligns with US naval modernization efforts to bolster unmanned operations, particularly in Indo-Pacific theaters. Ryan Maatta, Serco’s Marine Engineer Manager, highlighted Defiant’s scalability and affordability, addressing historical cost barriers in unmanned systems.
USVs present a paradigm shift in naval warfare, offering significant tactical advantages and notable vulnerabilities.
Their cost-effectiveness enables cash-strapped navies to deploy swarms of autonomous attack boats, as evidenced by Ukraine’s successful use of USVs against Russian warships. These drones, with low profiles and AI-driven evasive maneuvers, can evade detection and overwhelm advanced naval defenses.
However, USVs are not a naval warfare panacea. The maritime environment accelerates mechanical degradation while increasing autonomy, making them prime cyber targets.
Their reliance on external communication links exposes them to jamming and hacking, particularly in a GPS-denied or electronic warfare-heavy environment.
Additionally, they lack the sustained endurance, firepower and adaptability of crewed warships, which will remain essential for prolonged naval engagements for the foreseeable future.
In a March 2023 Center for International Maritime Security ( CIMSEC ) article, Kyle Cregge highlights the potential role of USVs in future naval operations.
Cregge says USVs embody the” Every Ship a Surface Action Group ( SAG )” model, augmenting manned combatants with scalable missile firepower and distributed lethality.
He mentions that USVs used as force multipliers enhance fleet survivability by complicating adversary targeting while offering economical Vertical Launch System (VLS ) expansion when the US Navy may face a firepower gap with China.
He notes that integrated with manned-unmanned teams ( MUM-T), these systems ensure flexible operational responses and rapid adaptability, embodying a cost-effective, strategically robust solution for deterring aggression and preserving maritime dominance in increasingly contested environments like the Taiwan Strait.
Paul Lushenko mentions in a July 2024 Proceedings article that the US Navy’s framework for unmanned systems at sea emphasizes integration across domains to enhance distributed maritime operations ( DMO ) and information warfare.
Lushenko says that key methods such as picket, distribution and mass offer advantages from early warning and situational awareness to overwhelming adversaries with coordinated strikes. He also adds that MUM-T, leveraging AI, optimizes decision-making and shortens sensor-to-shooter timelines.
Highlighting the critical importance of ship numbers in naval operations, Sam Tangredi mentions in a January 2023 Proceedings article that historical evidence shows fleet size often trumps technological superiority in naval warfare, as demonstrated by 28 analyzed conflicts from ancient times to the Cold War.
Tangredi points out that in 25 cases the larger fleet prevailed, with technological advantages proving short-lived and outweighed by mass. He says superior numbers facilitate better scouting, operational flexibility and striking capacity, as seen during the Napoleonic and World War II eras.
He mentions that US Navy expansions, like the 600-ship Cold War strategy, embraced these principles. Conversely, Tangredi mentions that a smaller, technologically advanced force rarely overcame its numerical disadvantage.
According to the US Department of Defense’s ( DOD ) 2024 China Military Power report, China’s People’s Liberation Army-Navy ( PLAN ) is the world’s largest navy with 370 ships, including 140 major naval combatants.
Underpinning China’s numerical advantage, an August 2024 US Congressional Research Service ( CRS ) report mentions that China has 230 times the US shipbuilding capacity, emphasizing that the gap is a significant liability for the US in competing with China.
Further, in a February 2025 Perry World House article, Bradley Martin mentions that the US Navy faces a complex web of challenges ranging from force design, persistent production delays, chronic cost overruns and dwindling shipbuilding capacity.
Martin says that despite ambitious targets like the 373-ship fleet supported by 150 unmanned vessels under the Force Design 2045 plan, execution often falters due to misaligned priorities and aging infrastructure.
He points out that the US Navy struggles with manpower shortages, service-life extensions of older combatants and a reliance on legacy technology.
He adds that the US Navy’s short-term crisis responses often exacerbate long-term readiness gaps, creating a vicious cycle of deferred maintenance and stretched resources.
USNI News recently reported that the Trump administration has unveiled an ambitious plan to overhaul the US shipbuilding industry to counter China’s dominance in global maritime production.
Central to the initiative is creating a new maritime industrial base office within the National Security Council. This office will develop a comprehensive maritime action plan within six months.
The plan includes imposing tariffs on imports arriving on Chinese-made ships, establishing a Maritime Security Trust Fund and offering tax incentives to revitalize domestic shipbuilding, Reuters reported citing a White House document.
The Trump administration also seeks to address procurement inefficiencies and increase wages for nuclear shipyard workers, signaling a strategic push to bolster national security and economic resilience.
However, Brian Clark and Michael Roberts mention in a December 2024 Hudson Institute report that it is not realistic for the US to match China hull-for-hull, and it is unfeasible for the US to offset China’s huge cost advantages while making US shipyards internationally competitive.
Clark and Roberts also argue that while getting ahead of the technology curve ( i. e., nuclear and hydrogen propulsion, modular construction ) is important, attempting to close the gap by massively investing in a particular set of technologies underestimates China’s capacity for technological innovation and cost-cutting.
As the US Navy bets on unmanned ships to bridge its numbers gap with China, the real battle may not be at sea—but in shipyards, supply chains and technological dominance, areas where China currently holds decisive advantages.