China testing underwater unmanned drones, can conduct long-range mission

China is reportedly testing large unmanned underwater drones, known as Extra-Extra-Large Uncrewed Underwater Vehicles (XXLUUVs), which are comparable in size to conventional diesel submarines but fully autonomous. These drones, over 131 feet (40 meters) long and likely powered by hybrid diesel-electric propulsion with large lithium-based battery banks, can carry more fuel, sensors, and weapons due to the absence of human crews. With an estimated range of around 10,000 nautical miles (18,520 km), they could traverse vast ocean distances, loiter for extended periods, and potentially conduct long-range missions such as blockading strategic sea routes like the Panama Canal or the U.S. West Coast. Intended to be armed with conventional submarine weapons like mines and torpedoes, these drones might also serve as motherships for smaller drones, although this capability is considered less certain. Their long endurance and stealth make them valuable for missions including mine-laying, undersea infrastructure attacks (