The US Navy's efforts to build a fleet of autonomous drones designed to deter a possible Chinese offensive against Taiwan have been plagued by a series of incidents and internal turmoil, a Reuters investigation has found.
During a US naval test off the coast of California last month that was intended to showcase the Pentagon's best autonomous drones, one unmanned vessel unexpectedly stalled. As officials tried to fix a software problem, another autonomous vessel slammed into the starboard side of the working boat, jumped the deck and crashed back into the water, an incident captured in videos reviewed by "Reuters".
The previously unreported incident, which involved two vessels built by U.S. defense technology rivals Saronic and BlackSea Technologies, is one of a series of recent setbacks in the Pentagon's efforts to build a fleet of autonomous ships, according to a dozen people familiar with the program.
Weeks earlier, during a separate Navy test, the captain of a support vessel was thrown into the water after another Blacksea Technologies autonomous vessel it was towing suddenly accelerated, capsizing the vessel, according to four people familiar with the incident. The captain was rescued and refused medical attention. The incident was first reported by Defense Scoop.
Both incidents resulted from a combination of software failures and human error, including communication failures between onboard systems and external autonomous software, according to sources familiar with the matter.
The Navy, Saronic and Blacksea Technologies declined to comment on the incidents.
The U.S. military sees naval drones as a key tool after their successful use in Ukraine, where cheap, $250,000-a-day remotely piloted boats struck a significant portion of Russia’s Black Sea Fleet. It has repeatedly said it needs autonomous swarms of aerial and naval drones to deter a potential Chinese incursion across the Taiwan Strait. Taiwan itself has begun acquiring its own naval drones.
"These systems will play a critical role in the future of naval warfare by extending the fleet's reach, improving situational awareness and increasing combat effectiveness," said Acting Chief of Naval Operations Jim Kilby during a visit to the BlackSea facility in June.
But some analysts say the recent failures show the Pentagon is far from achieving reliable autonomy.
After the crashes, the Defense Innovation Unit (DIU) has suspended a nearly $20 million contract with L3Harris, a company that supplied software used in some of the tests. L3Harris said it stands by the safety and reliability of its products but declined to comment in detail.
In 2023, the Pentagon launched the $1 billion Replicator program to rapidly produce thousands of air and sea drones. The first systems are expected this month. BlackSea has already received at least $160 million to produce dozens of the reconnaissance boats per month. Saronic, valued at $4 billion and backed by venture capital, is also in the running, but has not yet won any major contracts.
The issue is a priority for President Donald Trump, who in the "big beautiful bill" passed last month provided almost $5 billion for maritime autonomous systems. However, the new administration has been skeptical of the Navy's current approach.
The key unit for procuring unmanned ships - PEO USC - has recently been rocked by scandal. Its head, Rear Admiral Kevin Smith, was fired for "loss of trust", and the program is under review and could be restructured or shut down. At a meeting last month, senior Pentagon officials expressed doubts about the cost-effectiveness and capabilities of the drones being acquired by the unit.
The shakeup comes as shipbuilders and software vendors seek to secure even larger autonomous maritime projects, such as unmanned submarines and cargo ships.
Last week, the USC PEO began accepting proposals for the Modular Attack Surface Ships to acquire medium- and large-sized vessels capable of carrying containers, surveillance equipment and conducting strikes.
Texas Hams, an expert on autonomous weapons and a fellow at the Atlantic Council, said the U.S. Navy is in uncharted waters as it tries to abandon decades of tradition and embrace a new paradigm.
"You have a system that is used to building big things, taking years to make a decision, and now all of a sudden you're asking them to act quickly," he said.