The Defense Department’s second Ghost Fleet Overlord Unmanned Surface Vessel (USV) completed a long-range autonomous transit from the Gulf Coast to the West Coast, passing through the Panama Canal, the Pentagon said Monday.

This USV, named Nomad, is the second of two Overlord USV test ships developed by the DoD Strategic Capabilities Office (SCO) and transiting at sea in partnership with the Navy.

DoD said the vessel traveled 4,421 nautical miles, with 98 percent of that in autonomous mode. This repeats the voyage of the first Overlord vessel, named Ranger, in October 2020. Notably, both vessels were set in manual mode while passing through the Panama Canal.

The department said this recent transit was an opportunity for extended testing of Overlord vessel endurance; autonomous operations; interoperability of government command, control, communications, computers and intelligence (C4I) systems with vendor autonomy, hull mechanical and hull electrical systems.

The remote mission command and control for the transit of Nomad occurred from an ashore Unmanned Operations Center operated by Navy sailors for Surface Development Squadron One (SURFDEVRON) in San Diego, Calif., where the department is testing and basing these prototype USVs. That unit also operates two Sea Hunter USVs and Zumwalt-class destroyers.

“This is another significant milestone for SCO’s Ghost Fleet Overlord program and supports the Navy’s Unmanned Campaign Framework by adding a second Overlord vessel to the West Coast. The SCO Ghost Fleet Overlord program serves to inform Navy prototype efforts by integrating mature technologies to accelerate Service priorities and is a key piece of the build a little, test a little, and learn a lot philosophy articulated in the Navy Unmanned Campaign Framework,” SCO Director Jay Dryer, said in a statement.

The Pentagon said the Overlord program is in its second phase, which began in September 2019, and “focuses on the integration of government-furnished command-and-control systems and payloads and more complex and challenging naval operations experimentation. Phase II is being conducted with the same vessels and industry teams that took part in Phase I and will conclude in early 2022, at which point both Ghost Fleet Overlord vessels will transition to the Navy for further experimentation.”

At SURFDEVRON in San Diego, the two Overlord vessels will continue to participate in fleet experimentation exercises to further mature autonomy systems, demonstrate system reliability, and explore employment concepts while stressing command and control systems.

“Both vessels will continue to provide key system data, enable fleet operator feedback, and demonstrate capabilities essential to continued maturation and development of USV concepts of operation,” the Defense Department said.

The overlord program is being executed by SCO in partnership with the Navy’s program Executive Office, Unmanned and Small Combatants.

“Our close partnership with SCO on the Overlord program is accelerating the technology demonstration, CONOPs [concept of operations] development, and operational command and control of unmanned surface vessels in direct alignment with the Navy’s plans,” Captain Pete Small, Navy Program Manager for USVs, said in a statement.

The department noted two more Overlord prototype USVs are currently under construction and will be used in further experimentation and testing.

In January, Small said new USVs will have a range of manning options as they are developed. As part of that, the Ghost Fleet Overlord vessels “are essentially optionally manned” with personnel onboard during previous long transits (Defense Daily, Jan. 19).

At the time, the Navy said the autonomy operations do not only cover straight passage through the ocean, but also collision avoidance and following the rules of sea transit, known as COLREGS.

“We have the ability to operate them remotely and, I’ll say, semi-autonomously to allow us to make advancements in demonstrating that autonomy capability while continuing to have people onboard for safety and technology readiness considerations,” Small said.