Underwater drones being tested by China could be used to blockade the Panama Canal or even the US west coast, an American defence publication has claimed. The drones, referred to as XXLUUVs (Extra-Extra-Large Unmanned Underwater Vehicles), are highly classified and little is known for certain about them. However, some clues have been gleaned from satellite imagery, eyewitness photographs and a builder’s concept model displayed at a defence exhibition, according to the Naval News website. The report said the drones were believed to be by far the world’s largest and to be capable of sailing more than 10,000 nautical miles (18,500km) – about twice the width of the Pacific – allowing them to reach the western Americas, including the strategically vital canal.

Full report : Evidence points to China developing XXL submarine drones that provide a ‘low-risk’ option for attacking key sites, according to a US defence website.