The US Navy has quietly confirmed its longest robotic submarine patrol to date, the Orca XLUUV, and the Pentagon isn’t saying what it was for.
The Navy has completed its first long-range patrol with the Orca XLUUV, the largest uncrewed submarine in its fleet. The vehicle traveled more than 1,000 nautical miles — about 1,852km — across the eastern Pacific in July with no one aboard. Rear Admiral Chris Cavanaugh, commander of the Submarine Force, US Pacific Fleet, disclosed the run in a statement released August 13, timed to the close of the RIMPAC 2026 exercise near Hawaii.
The milestone, reported August 15, was described as a first for the program. Even so, the Navy has released few details — it hasn’t named the route, the cargo, or the mission.
Cavanaugh said the Pacific Submarine Force is “heavily investing in unmanned capabilities to augment our manned submarines.”
A First for the Program
The July run capped a busy year for the Navy’s undersea robotics efforts. Cavanaugh’s release also cited the USS Delaware, which launched and recovered a smaller drone through its torpedo tubes off Norway in 2025.
Separately, Cavanaugh met Rear Admiral Marcos Jasso, commander of Carrier Strike Group 9, aboard the USS Theodore Roosevelt on July 30. The two discussed integrating uncrewed submarines into carrier operations, including using them to ferry spare parts between submarines and carriers — allowing a submarine to resupply without ever surfacing.
What Is the Orca XLUUV?
XLUUV stands for extra-large uncrewed undersea vehicle — in plain terms, a robot submarine roughly the size of a subway car. Boeing builds it with Huntington Ingalls Industries, based on Boeing’s earlier Echo Voyager design.
The bare hull measures about 16 meters; with its modular payload section attached, it stretches to roughly 26 meters and displaces about 85 tonnes. Boeing lists a range of 6,500 nautical miles (about 12,000km) on a hybrid diesel-electric power plant. The payload bay alone runs about 10 meters long and can carry up to eight tonnes. Notably, Orca launches from a pier — it requires no mother ship or submarine to deploy it.
Delivery has run behind schedule. Boeing handed over a test vehicle, XLE0, in December 2023, though the 2019 contract had called for the first batch by the end of 2022. Boeing christened its latest vehicle, XLE2, in March 2026
Orca’s Intended Missions
The Navy reportedly acquired Orca to meet an urgent operational need tied to the Pacific, with four core missions: intelligence gathering, mine warfare, seabed warfare, and expeditionary support.
Mine laying appears to be the priority. Orca will carry “Hunter,” a payload designed to deliver mines into heavily defended waters. Naval News has also reported a previously undisclosed system for launching heavy torpedoes from a distance, with Hunter’s own timeline tied to that development.
In 2024, naval analyst H.I. Sutton noted that the vehicle’s large payload hatches appeared “consistent with mine laying missions.” That payload includes Hammerhead, a mine tethered to the seabed and armed with a torpedo. Reports from March indicate the Navy is expanding its Hammerhead order, with seafloor-mapping sonar potentially to follow.
Timeline and Target
Officially, the Navy names no adversary for the Orca program. Unofficially, geography does the talking.
The May 2026 shipbuilding plan moved Orca from experimental status to a funded purchase, allocating $135.8 million for two vehicles in fiscal year 2027. In total, 16 vehicles are planned by 2031 at a cost of about $1.13 billion. A formal acquisition strategy for the Hunter mining payload is expected in late 2027 or early 2028. Forward deployment timelines have slipped before — a Navy program manager told a 2023 symposium that Orca would deploy overseas by 2026.
Auditors have remained skeptical. The Government Accountability Office raised concerns in June 2025, by which point the program had absorbed roughly $885 million. It remained “unclear whether the Navy will transition the XLUUV to a program of record,” auditors wrote.
The strategic target, while unstated, is not hard to infer. Orca was originally acquired to meet an Indo-Pacific Command requirement for an underwater minelayer — a capability that could help deny Chinese forces a landing on Taiwan or block a dash through key maritime chokepoints. The Navy’s own Navigation Plan explicitly ties its robotics investment to strategic competition with China.
An Undersea Arms Race
Rivals and allies are moving fast in the same direction. Anduril’s Ghost Shark reached production for Australia in under four years and is now being pitched to Washington. Britain delivered the XV Excalibur to the Royal Navy in December 2025.
China offers the closest direct comparison. Beijing unveiled its AJX002 uncrewed submarine in September 2025, capable of carrying up to 20 mines with a reported range of 1,000 nautical miles — almost exactly the distance the Orca XLUUV has just proven it can travel.
