Large or extra-large unmanned undersea vehicles (LUUV or XLUUV) are a class of autonomous underwater vehicles (AUVs) that are significantly larger than traditional AUVs, which are typically used for tasks like surveying or mine countermeasures. Unlike smaller AUVs, XLUUVs are designed to operate for extended periods and carry larger payloads over vast distances without direct human control.
Design and characteristics XLUUVs are characterized by their size and endurance. While there's no international standard for what constitutes "extra-large," the Naval Sea Systems Command of the United States Navy considers an extra-large unmanned undersea vehicle to have a diameter of at least and be capable of extended range and endurance.
Primary roles and applications
The primary purpose of XLUUVs is to operate in environments that are too dangerous or difficult for manned submarines. Their key applications include: Intelligence, surveillance, and reconnaissance (ISR): They can covertly patrol large areas of the ocean, collecting data on a persistent basis. Mine countermeasures: XLUUVs can be used to locate and neutralize underwater mines, keeping manned vessels out of harm's way. Anti-submarine warfare (ASW): They can act as a persistent listening post or a launch platform for anti-submarine weapons. Seabed warfare: With their long endurance and superior stealth compared to manned systems, they are a cost-effective expandable tool. Payload delivery: Their large size allows them to deploy smaller AUVs, sensors, or other equipment to remote locations.
The development of XLUUVs is a key area of research for navies around the world, particularly as they seek to expand their undersea capabilities with autonomous and cost-effective platforms.
(X)LUUV projects Project Origin Designer and/or Builder Planned operators Status Source Ghost Shark Anduril Industries In production SeaWolf Cellula Robotics Royal Australian Navy In development Speartooth C2 Robotics In development Solus-XR Cellula Robotics In development AJX-002 HSU-001 HSU-100 UUV-300 UCUV Naval Group In development MUM TKMS n/a Study Jalkapi Krishna Defence and Allied Industries LtdIn production Kapal Selam Otonom PT PAL In development BlueWhale ELTA Systems In development LUUV Mitsubishi Heavy Industries In development Cephalopod Rubin design bureau In development Harpsichord-2P-PM Rosoboronexport In development Sarma-D Lazurit Central Design Bureau In development Combat XLUUV Hanwha Ocean In development LUUV Saab Kockums In development National Chung-Shan Institute of Science and Technology Lungteh Shipbuilding In operation Black Whale Longteh Shipbuilding In development XLUUV Dearsan In development STM Tengiz STM In development https://defenceturkey.com/news/the-unmanned-guardian-of-the-deep-stm-elevates-naval-defense-with-tengiz-xluuv-autonomous-platform DATUM Sinarit Datum In development https://www.navalnews.com/naval-news/2026/05/datum-introduces-strike-capable-sinarit-xluuv/ Cetus MSubs In development Herne BAE Systems In development Manta MSubs n/a Experimental Echo Voyager Boeing Phantom Works n/a Experimental Orca Boeing Huntington Ingalls Industries In development
See also Unmanned underwater vehicle Autonomous underwater vehicle Unmanned surface vehicle Large Unmanned Surface Vehicle
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