This story originally featured on The War Zone.

The Pentagon’s Strategic Capabilities Office, or SCO, is adding two more unmanned surface vessels, or USVs, to its secretive Ghost Fleet Overlord program, which it is running in conjunction with the U.S. Navy. In addition to the pair of new ships, SCO has announced that it will transfer the two existing USVs it has been testing to the Navy in January 2022. 

The SCO’s Ghost Fleet Overlord program, which dates back to at least 2017, aims to rapidly field autonomous surface vessels in order to “better expand the reach of manned vessels,” according to the Pentagon. The project has been looking to develop ships that can not just travel from point A to point B on their own, but also follow the rules of the sea and avoid other ships autonomously. The announcement about the two new vessels comes amid many other recent developments signaling the Navy’s increased emphasis on unmanned vessels

“The intent is to utilize this time period to do fleet demonstration exercises and operational vignettes to continue to demonstrate in an operational context the utility of these vessels to augment manned combatant capabilities,” Luis Molina, SCO’s deputy director told reporters this week.

The SCO’s two existing large unmanned surface vessels (LUSVs) for the Ghost Fleet Overlord program, the Ranger and the Nomad, were converted from commercial fast supply vessels, which are typically used to support various offshore activities, such as work on oil platforms and around offshore wind farms. As such both of them feature large open spaces in the rear, originally intended to carry cargo, which can be readily reconfigured to accommodate different payloads.

Since October 2020, both of the USVs completed autonomous transits from the Gulf of Mexico to the West Coast of the US, operating in human-controlled modes only when traversing the Panama Canal. The most recent voyage, carried out by the Nomad, saw the USV travel over 4,000 miles in June 2021 with 98 percent of the trip completed autonomously.

Now, the SCO is set to add two more similarly-sized autonomous ships to the program. Little is known about the new vessels, or their manufacturers. For security reasons, the SCO is not releasing the names of the firms developing its new unmanned surface vessels in light of recent security breaches among Navy contractors. “We are developing cutting-edge technologies for the future fight. We’re trying to protect those investments from being stolen by our adversaries,” Molina said this week. “As a result of that, we [SCO] do not normally provide the names of our industry teams.”

In order to control its growing fleet of unmanned assets, the Navy has been working with Raytheon in the development of a Common Control System (CCS), an effort designed to help unify future operations involving various autonomous platforms, such as the MQ-25A Stingray aerial tanker drone, submarine-launched Large Displacement Undersea Vehicles (LDUUVs) like the Snakehead, and other experimental USVs. The Navy is also planning to incorporate other existing unmanned platforms into the system in the future, such as the MQ-8 Fire Scout

As part of its plan to develop new medium and large USVs, the Navy has requested $144.8 million for Fiscal Year 2022. The House Appropriation Committee, however, has proposed cutting $42 million from the program.

Read the rest of the reporting over at The War Zone.