How to Build and Operate a 500-Ship U.S. Navy

By Lt. Cmdr. U.H. (Jack) Rowley, USN (Ret.)

In an address at the 2022 AFCEA/US Naval Institute “West” conference, Chief of Naval Operations Admiral Michael Gilday revealed the Navy’s goal to reach 500 ships by adding approximately 150 unmanned maritime vehicles to the Navy’s inventory. This plan added additional detail to the Navy’s Unmanned Campaign Framework.

Most recently, previous speeches and interviews alluding to the number of unmanned surface vehicles the Navy intends to field culminated in the issuance of the Chief of Naval Operations NAVPLAN 2022 and Force Design 2045, both of which call for 350 manned ships and 150 large unmanned maritime vehicles. These official Navy documents provide the clearest indication yet of the Navy’s plans for a future fleet populated by large numbers of unmanned surface vehicles (USVs).

However, Congress has been increasingly reluctant to authorize the Navy’s planned investment of billions of dollars on USVs until the service can come up with a concept of operations for using them. In fairness, Congress has a point. The Navy has announced plans to procure large numbers of unmanned systems especially large and medium unmanned surface vehicles—but a concept of operations, one in even the most basic form, has yet to emerge.

While the Navy appears to be committed to buying large numbers of unmanned surface vehicles, it must come up with a convincing concept of operations for how they will be used during a conflict against a determined adversary. Unless or until the Navy can evolve such a concept, it is unlikely that a 500-ship fleet populated by 150 unmanned surface vehicles will ever reach fruition.

A Bridge to the Navy After Next

During the height of what has become known as the Reagan defense buildup in the mid-1980s, the Navy evolved a strategy to build a “600-ship Navy.” That effort resulted in a total number of Navy ships that reached 594 in 1987. That number has declined steadily during the past 35 years, and today the Navy has less than half the number of active, commissioned ships it had then.

The increasing cost to build ships, and especially the cost to man these vessels (70 percent of the total ownership costs of surface ships is the cost of the personnel who operate these vessels over their lifecycle), and the fact that the Navy is literally wearing these ships out more rapidly than anticipated, and it is easy to see why the Navy has great difficulty growing the number of manned surface vessels.¹

The rapid growth of the technologies that make unmanned surface vehicles increasingly capable and affordable has provided the Navy with a potential way to put more hulls in the water. This has led to the Navy’s commitment to field a force comprising 150 large and medium unmanned surface vehicles.²

Some have noted that the Navy’s Unmanned Campaign Framework is high on aspiration but low on specifics.³ Said another way, this vision is good as far as it goes, but the Navy has endured withering criticism from a skeptical Congress that is not warm to the service spending billions of dollars on USVs until the Navy can come up with a concept of operations for using them.

As the Navy looks to allay congressional concerns and accelerate the fielding of unmanned maritime systems, the emphasis should be on no longer thinking of each unmanned maritime system as a “one-off,” but rather to package these together as multiple-sized and multifunction vehicles designed for specific missions.⁴ The emphasis must remain on USV ship design that is modular to accommodate sensors, weapons, and payloads for specific missions, where the platform remains constant and the modularity within the platform allows for the “modular shift” to support multiple missions.⁵

A Concept of Operations

The concept of operations proposed is to marry various size unmanned surface, subsurface, and aerial vehicles to perform Navy missions—current and future—as the Navy After Next evolves. Simply put, the Navy can use the emerging large unmanned surface vehicle as a “truck” to move smaller unmanned vehicles into the battle space in the increasingly contested littoral and expeditionary environment.

There are numerous important Navy missions this integrated unmanned solution could accomplish, but this article will focus on two: intelligence, surveillance, and reconnaissance; (ISR) and mine countermeasures (MCM). There are many large, medium, small, and ultrasmall unmanned systems that can be adopted for these missions. The technical challenge remains that they must be designed to ensure that the “multiple sized” unmanned systems associated with these missions can be adapted to work together in a common mission goal.

This article will offer concrete examples using commercial unmanned systems that have been employed in recent Navy and Marine Corps events. In each case, these systems not only demonstrated mission accomplishment, but also the hull, mechanical, and electrical attributes and maturity that Congress is demanding before proceeding ahead with robust acquisition of Navy unmanned systems.

While there are a wide range of medium unmanned surface vehicles (MUSVs) that can potentially meet the Navy’s needs, there are three unmanned surface vehicles that appear to be furthest along in the development cycle. These vehicles cover a wide range of sizes, hull types, and capabilities.

The Vigor Industrial Sea Hunter and the follow-on Sea Hawk are the largest of the three. The Sea Hunter was launched in 2016 and was built at a cost of $20 million.

  • A 132-foot-long trimaran with twin screws, powered by two diesel engines
  • Weighs 135 tons, which includes 40 tons of fuel; the craft can carry a payload up to an additional 10 tons
  • Cruise speed of 12 knots and a burst speed of 27 knots
  • Designed to be under way unmanned for 70 days; at cruise speed, it will have a range of 10,000 nautical miles
  • Can operate in sea state 5 and be survivable in sea state 7.
  • \The Textron monohull Common Unmanned Surface Vessel, now referred to as the MCM-USV, features a modular, open architecture design.
  • A length of 39 feet, a beam of 11 feet, and a draft of 26 inches
  • Propulsion is provided by a twin-screw diesel
  • Weighs 17,000 pounds and can carry a payload of up to 3,500 pounds
  • A cruise speed of 12 knots with burst capability up to 35 knots
  • An endurance range at cruise speed of 1,200 nautical miles
  • Designed to operate in sea state 4 and be survivable in sea state 5.

The Maritime Tactical Systems catamaran hull unmanned surface vehicles include the Devil Ray T24, T38, and T50 craft. All three of these USVs feature a modular and open architecture design. The composite carbon fiber hull is designed to minimize the hydrodynamic drag by moving the laminar-to-turbulent flow breakpoint further aft.

  • The T24, T38, and T50 range in size from 24-50 feet long, in beam from 10-12 feet wide, and in draft from 14-28 inches depth
  • Weight varies from 7,300-13,000 pounds, with payloads ranging from 1,800-10,000 pounds
  • Cruise speeds vary from 15-40 knots, with burst speeds from 60-80 knots
  • At cruise speed, the vehicles’ endurance range varies between 600-2,000 nautical miles
  • The vehicles can operate in sea state 4/5 with survivability in sea state 7.

Each of these MUSVs is a viable candidate to be part of an integrated unmanned solution concept of operations. Part of evolving an operational concept for employing unmanned surface vehicles involves placing them in the environment where they can perform their missions of ISR and MCM. This is not a trivial task, especially since the United States must be prepared to deal with peer and near-peer adversaries with robust anti-access and area denial capabilities.

If the Navy wants to keep its capital ships out of harm’s way, it will need to surge unmanned maritime vehicles into the contested battlespace while its manned ships stay out of range of adversary systems, sensors, and weapons. Small and medium USVs, unmanned aerial vehicles, and unmanned undersea vehicles need a larger vehicle (LUSV) to deliver them to an area near the battlespace. The Navy envisions LUSVs as being 200 feet to 300 feet in length and having full-load displacements of 1,000-2,000 tons.⁶

Depending on the size that is ultimately procured, the LUSV could carry several MUSVs and deliver them, largely covertly, to a point near the intended area of operations. MUSVs would then be sent independently to perform the ISR mission, or alternatively, could launch one or more smaller vehicles. Building on work conducted by the Navy laboratory community and sponsored by the Office of Naval Research, the T38, for instance, will have the ability to launch unmanned aerial vehicles to conduct overhead ISR.

For the MCM mission, the LUSV can deliver several MUSVs equipped with mine-hunting and mine-clearing systems. These vessels can then undertake the “dull, dirty, and dangerous” work previously conducted by Sailors who had to operate in the minefield. Given the large mine inventory of peer and near-peer adversaries, this methodology may well be the only way to clear mines safely in the future.

This scenario and concept of operations is built around an expeditionary strike group that is underway in the western Pacific. This strike group includes three LUSVs under supervisory control from a large amphibious ship. The Chief of Naval Operations suggested this concept of operations in early 2022 when he noted that he “wants to begin to deploy large and medium-sized unmanned vessels as part of carrier strike groups and amphibious ready groups in 2027 or 2028, and earlier if I can.”⁷

Supervisory control of these three LUSVs is provided from a control station on a single ship. The supervisory control station includes seating for a single operator who controls multiple USVs, in addition to an adjoining sensor/payload operator monitoring and controlling the mission sensors/payloads onboard each of the craft. A single supervisory operator station will be required for each LUSV. The LUSV will then be further configured with multiple smaller unmanned vehicles.

Operational Scenario

The expeditionary strike group in the western Pacific is on routine patrol about 500 nautical miles from the nearest landfall. An incident occurs in their operating area and the strike group is requested to obtain reconnaissance of a near-shore littoral area, associated bays, and river accesses and determine if the entrance to a specific bay has been mined to prevent ingress. The littoral coastline covers 200 nautical miles. This area must be reconnoitered within 24 hours without the use of air assets.

Command staff decides to dispatch the three LUSVs for the mission: two are configured with four MUSV-ISR craft each and the third is configured with four MUSVMCM vessels. The single supervisory control station for the three LUSVs remains manned in the mothership for the initial transit to the MUSV departure point, at which time two other control stations will be manned to provide further supervisory control.

The three LUSV depart the strike group together in a preset autonomous pattern for 250 nautical miles to a waypoint that is central to the 200-nautical-mile ISR scan area, 250 nautical miles from shore. At this waypoint, each LUSV will stop and dispatch the smaller craft and then wait at this location for their return. Steaming at a cruise speed of 25 knots, the waypoint is reached in about ten hours. At the dispatch waypoint,

the two additional supervisory control stations are manned (now one per LUSV) and command is given by the supervisory controllers to launch the smaller USVs.

Two MUSV-ISR craft are launched from each of the two ISR LUSVs. The autonomous mission previously downloaded specifies a waypoint location along the coast for each of the four craft. These waypoints are 50 nautical miles apart from each other, indicating that each of the four MUSVs will have an ISR mission of 50 nautical miles to cover.

Two MUSV-MCM craft are launched from the third LUSV. The autonomous mission previously downloaded has them transit independently along different routes to two independent waypoints just offshore of the suspected mine presence area, where they will commence minelike-object detection operations.

In this manner, each of the six craft will be transiting independently and autonomously to their next waypoint which will be the mission execution start point. The transit from the LUSV launch point, depending on the route, will be about 250-300 nautical miles to their nearshore waypoints. Transit will be at 70-80 knots to their mission start waypoint near the coast. Transit time is between four and five hours.

The plan is for each of the MUSV-ISR craft to complete their scan in four to five hours each, and for the two MUSV-MCM craft to scan the sea bottom and the water column for the presence of mine-like objects in four to five hours at a scan speed of six to eight knots.

The MUSVs transit to the objective area and conduct their missions. The timeline for the entire mission is as follows:

  • LUSV detach strike group to launch point and deploy six MUSVs: 10-12 hours
  • MUSVs transit from launch point to ISR/MCM mission start waypoints: 4-5 hours
  • ISR/MCM mission time from start to completion: 4-5 hours
  • MUSVs transit from mission completion point back to LUSV for recovery: 4-5 hours
  • LUSV recover MUSVs and return to strike group: 1012 hours

Even with the expeditionary strike group 500 nautical miles from shore, the strike group commander had the results of the ISR and MCM scan of the shoreline littoral area within 20-24 after the departure of the LUSVs from the strike group. The LUSVs were back on station in the strike group in less than 40 hours, ready for the next mission scenario.

Moving Forward with Effective Deployment

The Chief of Naval Operations envisions large and medium unmanned vessels as part of carrier strike groups and amphibious ready groups later this decade. His goal is to take an evolutionary approach and to scale up unmanned surface vessels in order to have large numbers of USVs available to commanders.⁸ This nested dolls approach can accelerate this effort.

I am certain that readers of Future Force can think of additional concepts of operation for ways that unmanned vehicles can perform missions that are important—and vital—for the Navy. I offer this one as a starting point for further dialogue in the community.

This is not a platform-specific solution, but a concept. When fleet operators see a capability with differentsized, commercial unmanned platforms in the water working together and performing the missions presented in this article, they will likely press industry to produce even more-capable platforms to perform these missions.

While evolutionary in nature, this disruptive capability delivered using emerging technologies can provide the Navy with near-term solutions to vexing operational challenges, while demonstrating to a skeptical Congress that the Navy does have a concept-of-operations to employ the unmanned systems it wants to procure.

¹ Megan Eckstein, “Navy Adds ‘Wholeness Balance Reviews’ to Budget Process to Consider Total Ownership Costs,” USNI News, January 18, 2018.

² Sam Lagrone and Mallory Shelbourne, “CNO Gilday: ‘We Need a Naval Force of Over 500 Ships’” USNI News, February 18, 2022; Sam Lagrone, “Navy’s Force Design 2045 Plans for 373 Ship Fleet, 150 Unmanned Vessels,” USNI News, July 26, 2022.

³ David Larter, “U.S. Navy’s New Unmanned Plan Has ‘Buzzwords and Platitudes’ but Few Answers,” Defense News, March 17, 2021.

⁴ Tim Gallaudet, “Three Ways the Navy Can Surge Its Unmanned Surface Force,” Real Clear Defense, February 26, 2022.

⁵ Justin Katz, “Navy Needs to Prep for Unmanned Integration, Says SWO Boss,” Breaking Defense, July 26, 2021.

⁶ Ronald O’Rourke, Navy Large Unmanned Surface and Undersea Vehicles: Background and Issues for Congress, CRS Report 45757.

⁷ Bradley Peniston, “Navy Chief Sees Robot Ships Alongside Aircraft Carriers Within Five Years,” Defense One, February 16, 2022; Sam LaGrone, “CNO Gilday Taking a More ‘Realistic’ Approach to Unmanned Systems in the Fleet,” USNI News, February 16, 2022.

⁸ Justin Katz, “From 7 Classified ‘Spirals’ to Coming Robotic Ships: Gilday on Navy’s Unmanned Task Force,” Breaking Defense, February 17, 2022; Megan Eckstein, “Unmanned or Minimally Manned Vessels Could Deploy Alongside Strike Groups as Soon As 2027,” Defense News, February 17, 2022.

Lt. Cmdr. Rowley is a retired surface warfare and engineering duty officer. He currently serves as the chief technology officer for Maritime Tactical Systems, Inc.

This article was published in Future Force, Volume 9, No.1, 2023 and is republished with the author’s permission.

Featured Photo: The MARTAC T-38 Devil Ray autonomous unmanned surface vessel (USV) built by Maritime Tactical Systems demonstrates an autonomous high-speed pass along the port side of the Spearhead-Class expeditionary fast transport vessel USNS Burlington (T-EPF-10) amongst onlookers from the Scientists-to-Sea program underway during the Navy’s Fleet Experimentation Program (FLEX), Oct. 17, 2022. FLEX aims to test various unmanned aerial and surface systems in order to strengthen and increase warfighter capabilities.


Photo by Petty Officer 1st Class Steven Khor 

U.S. Naval Forces Southern Command / U.S. 4th Fleet