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.
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 54 inches (140 cm) and be capable of extended range and endurance.
The primary purpose of XLUUVs is to operate in environments that are too dangerous or difficult for manned submarines. Their key applications include:
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.