General Atomics' new underwater drones target multi-year missions to support US submarine surveillance operations.

On November 3, 2026, General Atomics Electromagnetic Systems (GA-EMS) released a video presenting its Ranger and GA-Ray (GRay) unmanned underwater vehicles (UUVs), coinciding with the opening of Euronaval 2026 in Paris, France. The designs combine buoyancy-driven gliding propulsion with blended-wing hulls to enable multi-year submerged deployments spanning up to 20,000 nautical miles. Ranging from 6.71 to 41.15 meters in length, the platforms feature adaptable payload bays designed to deploy sub-drones, sensor networks, or ISO-container-sized cargo to supplement US Navy submarine operations.

General Atomics' GA-Ray (GRay) and Ranger are buoyancy-propelled autonomous underwater gliders designed for long-range surveillance and payload transportation, with the GRay intended for missions lasting weeks to months and the larger Ranger targeting multi-year operations. (Picture source: GA-EMS)

On November 3, 2026, General Atomics Electromagnetic Systems (GA-EMS) released a video presenting its Ranger and GA-Ray (GRay) unmanned underwater vehicles (UUVs), outlining plans for submerged operations lasting several years and missions extending across tens of thousands of nautical miles. The two designs use buoyancy-driven propulsion and blended-wing hulls to reduce the energy required for long-distance movement, rather than relying continuously on propellers. The GRay measures 6.71 m and serves as a development vehicle for propulsion, navigation, and payload integration, while the proposed Ranger extra-large UUV (XLUUV) would measure 30.48 to 41.15 m and accommodate substantially larger cargo.

Submerged testing involving the host and subordinate vehicles has reached 70 days, equivalent to 1,680 hours, compared with 26,280 hours for a three-year mission. The principal development challenge is therefore not simply extending underwater range, but maintaining navigation accuracy, electrical power, mechanical reliability, and useful sensor operation throughout deployments that could exceed the endurance of conventional battery-powered UUVs by several orders of magnitude. The GRay's 6.71 m hull incorporates hydrodynamic lifting surfaces, directional controls, supplementary thrusters, energy storage, sensors, and an adaptable payload compartment, with intended missions lasting weeks to months.

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The Ranger, for its part, would increase overall length by a factor of 4.54 to 6.13, with one proposed configuration incorporating a wingspan of 30 m, creating additional internal space for ballast equipment, energy storage, and mission cargo. Under purely geometric scaling, those length ratios would correspond to volume increases of 94-231 times if both vehicles retained identical proportions, although actual displacement and usable internal volume remain unspecified. One intended cargo arrangement is comparable to a 20-ft ISO container, whose external dimensions of 6.058 × 2.438 × 2.591 m correspond to 38.3 m³, while alternative arrangements could accommodate dozens of smaller UUVs or two larger underwater vehicles.

Logically, these configurations would require different launch mechanisms, electrical interfaces, structural supports, and ballast adjustments, particularly when equipment is released underwater and changes the vehicle's weight distribution, but neither Ranger's maximum payload mass nor its full-load displacement, operating depth, and cargo-handling limits have been disclosed. The propulsion architecture is intended to exchange transit speed for reduced electrical consumption, using changes in buoyancy to generate repeated descending and ascending trajectories while hydrodynamic lift produces forward movement. Supplementary thrusters provide maneuvering capability, but prolonged powered operation would increase energy consumption and reduce the advantages of gliding.

How General Atomics' Ranger could travel 20,000 nautical miles underwater

At illustrative lift-to-drag ratios of 4:1 and 8:1, a 500 m descent would generate 2 km and 4 km of horizontal travel, respectively, excluding ocean currents and maneuvering losses. The intended operating distances extend between 10,000 and 20,000 nmi, equivalent to 18,520 to 37,040 km, although GA-EMS has not established a sustained Ranger transit speed with operational cargo installed. Traveling 5,000 nmi would require 417 days at 0.5 knots, 208 days at 1 knot, 104 days at 2 knots, or 69 days at 3 knots, demonstrating how relatively small speed differences can alter deployment schedules by several months. A 20,000-nmi mission completed over two years would require an average of 1.14 knots without stationary periods, or 2.28 knots during movement if half the deployment were allocated to fixed-position surveillance. Consequently, the design's operational relevance lies primarily in missions where extended presence and low energy consumption are more important than rapid repositioning. 

The proposed multi-year endurance also introduces electrical and mechanical requirements that cannot be assessed solely from propulsion efficiency. Over three years, continuous electrical loads of 100 W, 250 W, and 1 kW would require 2.63, 6.57, and 26.28 MWh, respectively, before accounting for conversion losses, reserve margins, or battery degradation. A 200 W acoustic sensor operating continuously would also consume 1,752 kWh annually, compared with 146 kWh when activated for two hours daily, thus reducing consumption by 91.7% but also substantially reducing the time available for active measurements. Buoyancy-driven movement can reduce machinery noise during glide phases, although ballast pumps, thrusters, actuators, and hydrodynamic flow remain acoustic sources, while the hull itself remains susceptible to active sonar detection. In its brochure, GA-EMS has not disclosed quantified radiated-noise measurements, usable electrical capacity, or the endurance achievable with continuously operating mission equipment.

What multi-year underwater missions would require from Ranger and GRay

Mechanical reliability is another limitation: under a simplified constant-failure-rate model, a component with a mean time between failures of 10,000 hours has a 7.2% probability of surviving 26,280 hours without failure, compared with 76.9% at 100,000 hours. For instance, the DARPA Manta Ray program, whose Northrop Grumman prototype completed in-water testing in February and March 2024, addressed similar engineering problems, such as underwater gliding, energy management, corrosion, biofouling, and long-duration autonomy. Long-duration missions also depend on maintaining accurate positioning and managing sensor information without continuous access to satellite communications. Consequently, both the Ranger and the GRay incorporate inertial navigation systems (INS) and Doppler Velocity Logs (DVL), allowing underwater movement to be estimated through inertial measurements and seabed-relative velocity when bottom tracking is possible.

At an illustrative positional error of 0.1% of distance traveled, a 10,000-nmi mission would accumulate 10 nmi of uncertainty, decreasing to 1 nmi at 0.01%, unless external position corrections or additional navigation references are available. Such errors could affect seabed equipment placement, acoustic sensor positioning, and the deployment of subordinate vehicles, particularly when multiple sensors must correlate detections across separate locations. Optical underwater communications could support high-rate exchanges over short distances, while quantum-enabled sensing is among the technologies being considered, although operational accuracy, integration status, and communication ranges remain unspecified. A sensor generating 100 kilobytes per second, for instance, would accumulate 8.64 GB daily, 605 GB over 70 days, and 3.15 TB annually; transmitting one day's collection through an effective 10-kilobit-per-second link would require 80 days. 

How Ranger could deploy smaller underwater drones and seabed sensors

The Ranger's larger hull could support distributed underwater operations by transporting multiple smaller vehicles to an assigned area before releasing them for localized surveillance, environmental measurements, or other missions. Proposed configurations accommodate smaller UUVs, two larger-displacement underwater vehicles, or a container-sized flexible payload bay, allowing mission planners to exchange the number of deployed sensors for greater individual endurance or cargo capacity. For illustration, a sensor with a hypothetical 5-nmi detection radius would cover 78.5 square nautical miles, while a seabed module could operate independently after release or remain connected to the carrier, with a continuous 100 W electrical load requiring 876 kWh annually and 2.63 MWh over three years, increasing to 4.38 and 13.14 MWh at 500 W.

As seen in the promotional video, GA-EMS has also experimented with a subordinate UUV releasing a tube-launched quadcopter, potentially extending underwater missions to short-duration aerial reconnaissance or communications. The practical value of the carrier arrangement, logically, will depend on how many subordinate vehicles can be deployed successfully, how accurately they reach assigned positions, and whether their collected information can be recovered or transmitted within operationally useful timeframes. The U.S. Navy's experience with extra-large underwater vehicles could already provide a procurement and operational reference for evaluating the Ranger's capabilities. Boeing's Orca XLUUV program began in August 2017, delivered its first test vehicle in December 2023 and a prototype in September 2025, and encompasses six development vehicles, including the test asset, with an estimated development expenditure of $879.64 million in FY2025 dollars.

The Orca completed a transit exceeding 1,000 nmi in the eastern Pacific in July 2026, while its intended missions include underwater mine deployment and potential integration of the Hammerhead encapsulated-torpedo mine. Other navies are also expanding their autonomous underwater capabilities: on September 30, 2026, the British Royal Navy announced a Mk48 Mod 4 torpedo firing from its XV Excalibur XLUUV, while the July 2026 Lanternfish exercise involved Ultra Maritime's Sea Spear sonar detecting and classifying medium- and large-diameter UUVs, with Anduril's Seabed Sentry and Lattice supporting detection integration. These developments indicate that underwater autonomy is expanding beyond reconnaissance into payload delivery and weapons integration, while counter-UUV surveillance systems are becoming more capable, since reduced machinery noise cannot prevent detection by all active acoustic sensors or fixed underwater surveillance networks. 

How Ranger and GRay could support U.S. Navy submarines and future fleet operations

Moreover, in its video, GA-EMS appears to suggest that its two UUVs could alleviate some of the demands placed on Virginia-class nuclear-powered attack submarines, which simultaneously conduct anti-submarine warfare, intelligence collection, land attack, special operations support, and naval formation protection. The Ranger could undertake selected missions that consume submarine availability without requiring the speed, weapons, or crewed tactical capabilities of an attack submarine. This approach aligns with the U.S. Navy's Hedge Strategy, introduced by Chief of Naval Operations Adm. Daryl Caudle in January 2026 and developed further in February, which combines the main battle force with mission-specific capabilities known as tailored offsets and tailored forces.

These formations are intended to address particular threats or geographical requirements without committing entire carrier strike groups or other high-end naval formations, whose deployment certification can take more than a year. The strategy also incorporates the Global Maritime Response Plan (GMRP), mission-specific Combat Surge Ready (CSR) certifications, and an Enhanced Mission Command Framework (EMCF) to improve readiness and decentralized command during distributed operations. Its potential scale is further illustrated by a November 2026 Hudson Institute fleet proposal incorporating nearly 1,600 robotic and autonomous systems, including 44 XLUUVs, 12 ultra-large UUVs, 115 large UUVs, 88 medium UUVs, and 144 relocatable sonars. These figures represent a proposed future force structure rather than approved Navy procurement quantities, but illustrate how long-endurance underwater vehicles such as the Ranger and the GRay could become part of geographically tailored surveillance and sea-denial forces operating alongside crewed submarines.

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Written by Jérôme Brahy

Jérôme Brahy is a defense analyst and documentalist at Army Recognition. He specializes in naval modernization, aviation, drones, armored vehicles, and artillery, with a focus on strategic developments in the United States, China, Ukraine, Russia, South Korea, Türkiye, and Belgium. His analyses go beyond the facts, providing context, identifying key actors, and explaining why defense news matters on a global scale.