China testing underwater unmanned drones that can conduct long-range missions: Report
https://interestingengineering.com/military/china-testing-underwater-unmanned-drones
The drones are likely intended to be armed with conventional submarine armaments like mines and torpedoes, but could also act as motherships for other drones, too. As for range, estimates have circulated of around 10,000 nautical miles (18,520 km) or more.
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. These new drones would provide some interesting new tools for the PLAN, especially given that such assets can be sent on one-way or high-risk missions with little to no risk to human crews.
They can also loiter in locations for long periods (weeks or months), making them excellent deterrents.