Manta Ray has been produced by Northrop Grumman. (File)
Manta Ray, a top-secret submarine prototype weapon of the US, was spotted by Google Maps docked at the Port Hueneme naval base in California on Sunday.
After an image of the same went viral, it was deleted and replaced with what multiple social media users believed were "edited" boats.
Manta Ray also caught attention for its similarity to a Star Wars vessel, a spaceship seen in the popular Hollywood franchise.
The autonomous vessel has been named after the sea creature due to its slick design and ability to anchor itself deep underwater while holding operations in low-power mode, the New York Post reported.
Manta Ray has been produced by Northrop Grumman as part of the US Navy project to develop long-range underwater weapons. This sophisticated underwater drone is said to be capable of hibernating on the seafloor for "very long periods" without refuelling.
Dr Kyle Woerner, Manta Ray programme manager at the Defense Advanced Research Projects Agency, earlier said that it 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," Dr Woerner said in the agency press release.
Dr Woerner further said that it was being designed with several payload bays of multiple sizes and types to enable it to a wide variety of naval mission sets.
In addition, Manta Ray's modular design allows the US Navy to disassemble and further transport it in ordinary shipping containers. This quality eliminates the necessity for requiring dedicated port facilities.
According to the Defense Advanced Research Projects Agency (DARPA), the vessel is a multi-phase effort, including at-sea demonstration of critical technologies. "The program is using a disciplined systems engineering approach to define demonstration system objectives and identify enabling technologies needed for future systems," it earlier noted.
A report in the Telegraph recently stated that the US Navy spent over three months testing the craft off the coast of Southern California.
Meanwhile, defence analysts have suspected that the US Navy's push to develop drone technology is to strategically counter the submarine operations by Russia and China.
Amid its ongoing war against Ukraine, Russia is said to be developing underwater drones of its own. Last year, the country announced its plans to acquire nearly three dozen such vessels.