Navy Ready to Christen New Overlord USV ‘Mariner’

The Navy’s newest medium unmanned surface vessel, soon to be christened Mariner, on display at the U.S. Naval Academy in Annapolis. *RICHARD R. BURGESS*

ANNAPOLIS, Md. — The U.S. Navy’s newest Overlord medium unmanned surface vessel (MUSV) is moored at the U.S. Naval Academy in Annapolis, Maryland, for its Aug. 23 christening ceremony after a period of tours by dignitaries, Navy officials, academy midshipmen and media reporters.

The MUSV, produced by prime contractor Leidos, with Gulf Craft of Franklin, Louisiana, as the builder, is to be christened “Mariner” by Stacy Small, wife of Capt. Pete Small, program manager for Unmanned Maritime Systems in the Program Executive Office, Unmanned and Small Combatants (PEO-USC).

The Mariner is the fourth Overlord MUSV to be acquired by the Navy, although the third vessel, Vanguard, is still under construction. The first two Overlord MUSVs, Ranger and Nomad, were built under the Strategic Capabilities Office’s Ghost Fleet Overlord Program and transferred to the Navy early in 2022. They are assigned to Unmanned Surface Vessel Division One in San Diego, California and participated in the Rim-of-the-Pacific Exercise off Hawaii this summer.

The Mariner, delivered to the Navy in March, recently completed a period at Little Creek, Virginia, for installation of some government-furnished equipment, said Brian Fitzpatrick, principal assistant program manager. Eventually it will be transferred to USV Division One via a transit of the Panama Canal.

Rear Adm. Casey Moton, program executive officer, PEO-USC, said the Overlord program is leveraging both at-sea and land-based testing. The at-sea testing is used to evaluate the performance of the MUSV in a corrosive salt-water environment.

Casey pointed out that each of the four Overlord vessels is different, with a variety of different hull, mechanical, and engineering systems and mission systems. Each MUSV also is evaluated with different mission systems that are changed out.

The Mariner, halfway built when the Navy bought it, is based on a fast supply vessel designed to service offshore oil rigs. The vessels are already significantly automated.

The MUSV is equipped with satellite communications; three radars of different bands; a mast-mounted electro-optical sensor, an electro-optical/infrared system camera system on six sides of the ship; Link 16; and several radios.

The Mariner, for example, can carry two 20-foot containers and four 40-foot containers on its aft section. The containers can contain mission systems, spare parts, weapons and other systems.

The Mariner can accommodate a small crew — including two merchant marine captains — as needed while the technology and concepts of operation for the MUSVs are evaluated. Fitzpatrick showed reporters the “red button” at the bridge control panel that allows a captain to take control of the ship if needed.

The Mariner is powered by five 2,000-horsepower diesel engines that drive five water jets. The ship also is equipped with bow thrusters. The ship was built with two generators but a third was installed by the Navy to provide power for the expected needs of the payloads, some of which may be deployed on the ship with their own power and cooling systems.

Redundancy is necessary on an unmanned ship more than a manned ship, and for each of its diesel engines the Mariner is equipped with three oil filters instead of one.

‘Pushing Boundaries’

The admiral said the Overlord vessels are designed to deploy in open oceans but declined to say they would be deployed to the Western Pacific, noting that the Ranger and Nomad deployed to Hawaii for RIMPAC.

Fitzpatrick said the Overlord MUSVs will need to be able to be refueled at sea, currently conducted by an onboard crew.

“We have to work through that,” he said.

Fitzpatrick said the program is collecting massive amounts of data — 400 terabytes so far — and has started to process it.

Moton said the Overlord program will influence the discussion in Congress and the Navy on the value and operation of MUSVs and that the program will have an impact beyond the U.S. Navy into the international maritime market, including commercial operations.

The Vanguard will be longer than the Mariner — 205 feet vice 19 feet — with a wider beam and greater capacity for payloads. Fitzpatrick said the program is “purposely pushing boundaries” with the Vanguard.