U.S. unmanned boat program hit by collisions as Pentagon accelerates $5 billion push to field maritime drones

Two training collisions involving unmanned U.S. Navy surface vessels off Southern California have raised fresh questions about the operational readiness of a rapidly expanding maritime drone effort that the Pentagon and the White House hope will help deter a Chinese attack on Taiwan.

In one incident on June 23, a tugboat captain who was towing an unmanned vessel out of Naval Base Ventura County was thrown overboard after the robot boat reportedly activated, accelerated and struck the support craft, capsizing it. A military spokesman said the event occurred "at approximately 3:28PM on June 23 within the Channel Islands Harbor Marina involving the overturning of a support boat by an unmanned vehicle that was being towed out of the harbor." The spokesman said a preliminary investigation indicated the unmanned vehicle "received an inadvertent command that turned the engine on, causing the towed vehicle to accelerate past and capsize the support boat," and that the training activity held an immediate safety stand-down and is implementing additional safety procedures.

Weeks earlier, Navy personnel reported a second exercise in which a high-speed unmanned surface vessel struck a stationary drone, hitting its bow, launching into the air and landing in the water. Details about damage or injuries in that instance were not released.

The incidents come as the Biden and Trump administrations have both endorsed large-scale investments in autonomous maritime systems. The recent bipartisan spending package dubbed by some supporters as the "Big Beautiful Bill" included almost $5 billion for maritime autonomous systems and testing, and a Pentagon program known as Replicator, launched about two years ago, seeks to mass-produce thousands of lower-cost unmanned surface and aerial systems under an approximately $1 billion effort.

Defense officials and planners describe unmanned surface vessels and other robotic platforms as a core element of a deterrent posture in the Indo-Pacific. A Navy document known as Project 33 directs that by 2027 the service "will integrate proven robotic and autonomous systems for routine use by the commanders who will employ them," with a stated aim of preparing for a possible conflict with the People’s Republic of China.

Adm. Sam Paparo, commander of U.S. Indo-Pacific Command, has used stark language to describe the concept, saying publicly that he wants to "turn the Taiwan Strait into an unmanned hellscape" to make adversaries' operations difficult and buy time for broader U.S. and allied responses. The approach draws on the recent battlefield use of low-cost, explosive-loaded unmanned surface vessels by Ukraine, which has demonstrated their potential to damage larger warships.

Bryan Clark of the Hudson Institute, who has studied naval innovation, said similar small, fast strike boats are attractive for Taiwan and U.S. planners because their low unit cost can make them expendable in large numbers and relatively easy to employ against approaching forces.

Despite the promise, the Navy has encountered programmatic and personnel setbacks. In May, Rear Adm. Kevin Smith, who had been the senior officer responsible for unmanned and small combatant programs, was relieved following an unspecified complaint; a Navy spokesman said the service "maintains the highest standards for leaders and holds them accountable when those standards are not met." Officials have also acknowledged pauses and delays in some software and acquisition lines tied to autonomy work.

At the same time, industry and Pentagon officials point to demonstrable progress. Last month the USX-1 Defiant, an unmanned 180-foot surface vessel designed to operate for extended periods without a crew, was unveiled. A Pentagon spokesman said about the vessel, "Defiant is a tough little ship and defies the idea that we cannot make a ship that can operate in the challenging environment of the open ocean without people to operate her." Private firms are also scaling up: the startup HavocAI has said it has built more than 40 unmanned boats and plans to field larger craft later this year.

Program managers say testing and experiments at locations including Naval Base Ventura County and Naval Base Coronado are intended to reveal limits and hazards before such systems are deployed in larger numbers. Navy documents emphasize readiness for potential conflict in the Indo-Pacific by 2027 while also aiming to preserve the service's long-term technological advantage.

Officials maintain that unmanned surface vessels remain a central part of future maritime operations, but the recent collisions and official personnel moves highlight the engineering, safety and organizational challenges of moving from prototypes and combat demonstrations to reliable, operational fleets. The Navy has said it is reviewing safety procedures and technical controls to reduce the risk of inadvertent activations and to safeguard crews involved in testing and towing unmanned systems.