Top secret US undersea drone 'Manta Ray' spotted on Google maps, removed after image goes viral

The submarine is built by Northrop Grumman as part of a US Navy project that involves developing long-range underwater weapons.

"Manta Ray" - a US submarine prototype weapon that has been shrouded in mystery - was recently spotted by Google Maps users, with pictures of it going viral on the internet.

According to a report in The New York Post, the submarine - which is an underwater drone - was seen docked at the Port Hueneme naval base in California. After its image got leaked online, Manta Ray disappeared and has been apparently replaced with boats.

The sub drone is named after Manta Ray - a cartilaginous fish that is known for its distinctive, broad, diamond-shaped body with triangular pectoral fins.

The vessel, which resembles the Manta Ray, has a slick design and can anchor itself deep underwater while operating in low-power mode, the NY Post said.

The submarine is built by Northrop Grumman as part of a US Navy project that involves developing long-range underwater weapons.

The report said that Manta Ray can hibernate on the sea floor for “very long periods” without a need for refueling.

Dr Kyle Woerner of Defense Advanced Research Projects Agency (DARPA), who was quoted by NY Post, said: "It [Manta Ray] uses efficient, buoyancy-driven gliding to move through the water ... our successful, full-scale Manta Ray testing validates the vehicle’s readiness to advance toward real-world operations."

Notably, the modular design of Manta Ray allows disassembly and transport in ordinary shipping containers, removing the need for dedicated port facilities.

The US Navy tested it off Southern California for over three months, the Telegraph reported.

Defense analysts believe US's drone technology is aimted at countering Russian and Chinese submarine operations.

Russians are developing underwater drones and plan to acquire nearly three dozen vessels. They claim their drone has a range of 6,200 miles, can be armed with nukes, and reach speeds up to 100 knots (115 mph).