China is reportedly testing large unmanned underwater drones that could be used to blockade important sea routes like the Panama Canal or the U.S. West Coast. These new drones would provide some interesting new tools for the People's Liberation Army Navy (PLAN), especially given that such assets can be sent on one-way or high-risk missions with little to no risk to human crews. Because such drones do not need to reserve space for human crews, they can dedicate more space to things like fuel, batteries, sensors, and, of course, weapons. They also reportedly have exceptionally long ranges, meaning they could potentially traverse the Pacific and loiter for long periods. Technically called an Extra-Extra-Large Uncrewed Underwater Vehicle (XXLUUV), these drones are not dissimilar in size to conventional diesel submarines but are completely autonomous. According to reports, the new submarines are over 131 feet (40 meters) long and most likely have a hybrid diesel-electric propulsion system. If reports are true, this could be a game-changer for China's People's Liberation Army Navy (PLAN), which has limited blue water assets. As for range, estimates have circulated of around 10,000 nautical miles (18,520 km) or more.
