Huge manta ray spotted off California. It's an underwater drone!

An underwater drone shaped like a giant manta ray has been fully tested in trials off the coast of southern California. Images of the huge uncrewed prototype vehicle which has been designed to carry out long-range operations for the US Navy have been released by the Pentagon's advanced research agency, Darpa. Built by the US defence company, Northrop Grumman, the drone is so large that it had to be delivered to the test area in subsections. No measurements have been publicly disclosed but it looks to be the largest underwater drone developed for the navy. The research programme is officially called the manta ray project. Another company, PacMar Technologies, based in Honolulu, Hawaii, is also developing a manta ray-shaped drone. Northrop Grumman said the drone had been designed to conduct "long-duration, long-range missions in ocean environments where humans can't go". It has been fitted with energy-saving technologies which will allow the drone to remain for long periods on the ocean floor using limited power while gathering intelligence or carrying other surveillance missions. Kyle Woerner, Darpa manta ray programme manager, said the "extra large UUV (unmanned underwater vehicle) could be rapidly assembled in the field". He said the successful sea trials had shown it was ready to advance towards " real-world operations". The manta ray drone, with four small propellers, glides gracefully through the water just like it's fish namesake and has been designed to carry out multiple missions. The aim is to have an underwater drone that can operate for nearly unlimited periods and could be launched from a warship. The entire system has been designed for "easy shipment in five standard shipping containers to support expeditionary deployment," Northrop Grumman said. The US Navy is focusing much of its new-technology programmes on developing unmanned surface and underwater vessels for future operations. China, too, is developing similar systems, although there is no evidence of a manta ray-shaped drone in current research programmes. China has been developing a range of advanced underwater vehicles, including large submarine drones. Satellite photos of the naval base on Hainan in the South China Sea have revealed two extra-large unmanned underwater vehicles.