Unmanned surface vehicle

Lore & Background

The development of USVs dates back to World War I, when Germany designed and used remote-controlled FL-boats to attack British warships. At the end of World War II, the US Navy used remote-controlled USVs for target drone and minesweeping applications. In the twenty-first century, advances in control systems and navigation technologies have produced USVs that can be controlled remotely from land or a nearby vessel, operate with partial autonomy, or function fully autonomously.

USVs vary in size from under 1 metre length overall to over 20 metres, with displacements from a few kilograms to many tonnes. Propulsion systems cover a wide range of power levels and interface types, including PWM-controlled electronic speed controllers, serial bus protocols, analogue interfaces, and proprietary CANbus protocols. A frequent challenge in USV control is achieving smooth response from full astern to full ahead, as crewed vessels typically have a deadband around the stop position that the control system must compensate for.

In oceanography and hydrography, USVs are valued for being more maneuverable than moored buoys and far cheaper than weather ships. Renewable-powered USVs, such as wave gliders and saildrones, can persist for months. Non-renewable-powered USVs serve as force multipliers in commercial survey; for example, the ASV Global 'C-Worker 5' collected 44% of a project's survey data in the Bering Sea, saving 25 days at sea.

Reader's Guide

The significance of USVs lies in their ability to perform tasks without risking human life, often at lower cost than crewed vessels. Their use has grown from military origins—remote-controlled boats in both world wars—to a wide range of civilian applications. The regulatory environment is evolving rapidly, as reflected in the Maritime Autonomous Surface Ship UK Industry Conduct Principles and Code of Practice 2020, developed by the UK Maritime Autonomous Systems Regulatory Working Group with contributions from organizations including the Maritime & Coastguard Agency, Atlas Elektronik UK, AutoNaut, Fugro, and others.

USVs have been predominantly used for environmental monitoring and hydrographic survey, with future uptake projected to grow in monitoring and surveillance of remote locations. Drivers for adoption include low operational cost, reduced risk to people, spatio-temporal efficiency, endurance, precision, and access to very shallow water. Notable achievements include the first fully autonomous sea voyage by the Soleil in January 2022, the first crewless coastal container ship voyage with docking by the MV Mikage in August 2022, and the first autonomous circumnavigation of Antarctica by a saildrone in 2019. The technology continues to advance, with autonomy platforms tailored specifically for USV operations being developed for various hull and propulsion configurations.

Did You Know?

• The British RNMB Harrier is an autonomous USV of the Atlas Elektronik ARCIMS mine warfare system.
• In January 2009, a passenger USV demonstration was held at Hampton, Virginia, United States.
• The saildrone was invented by British engineer Richard Jenkins, founder and CEO of Saildrone, Inc.
• In 2020, the British USV Maxlimer completed an uncrewed survey of 1,000 sq km of seafloor in the Atlantic Ocean.

Two Philosophies of Underwater Operation

Unmanned underwater vehicles divide into two fundamentally different operational philosophies: remotely operated and autonomous. Remotely operated vehicles (ROUVs) exist to replace human divers in dangerous conditions, carrying out surveillance, patrolling, and industrial or educational tasks. Because they cannot function without a live operator at the controls, their design carries inherent constraints. A typical ROUV carries a camera, actuators, sensors, and often a mechanical gripper for grasping objects. That gripper can disrupt the vehicle's weight balance, meaning a human must constantly assist with stabilization. In high-stakes scenarios the need for operator involvement becomes even more critical. The U.S. Navy's Submarine Rescue Diving Recompression System, for example, is a massive vehicle capable of saving up to sixteen people at depths reaching two thousand feet, and its life-saving mission demands dedicated human operators at all times. Autonomous vehicles, by contrast, operate entirely without an operator aboard, ranging from just a few kilograms to several tons in mass.

From Arctic Pioneers to Solar-Powered Endurance

The story of uncrewed underwater technology begins in 1957 when the University of Washington's Applied Physics Laboratory built the Special Purpose Underwater Research Vehicle, or SPURV, to gather oceanographic data in Arctic waters. Weighing 484 kilograms, it could descend to 3,650 meters and stay active for roughly five and a half hours, serving in that research role until 1979. The 1970s brought the SCAT AUV and the L1 and L2 models in 1974, aimed at technology development and oceanographic mapping. In 1983, ISE Ltd. partnered with International Submarine Engineering to create ARCS, a 32-bit Motorola-processor-driven platform that first dove in 1987 and tested improvements in battery life, navigation, and communications. A pivotal innovation arrived in 1987 when the Russian Institute of Marine Technology Problems introduced the Solar Autonomous Underwater Vehicle, mounting solar panels that enabled longer missions, more frequent GPS use, and heavier payloads without retrieving the vehicle for recharging. By 1995, battery advances made underwater gliders practical, enabling dives lasting weeks or even months.

Geopolitical Flashpoints and Wartime Deployment

Uncrewed underwater vehicles have drawn sharp geopolitical attention in recent years. On December 16, 2016, a Chinese warship in the South China Sea seized an underwater drone that the U.S. Navy survey ship USNS Bowditch was in the process of retrieving. The Pentagon confirmed the device was unarmed and used for gathering weather and temperature data. China's Defense Ministry announced the following day that it would return the drone, and it was handed back within several days. Far more consequential was the Ukrainian conflict. After successful military use of uncrewed surface vehicles in the Black Sea in late 2022, the Ukrainian Navy began deploying the Toloka TLK-150, a 2.5-meter robotic submarine with twin thrusters on wing-like stabilizers, developed by Brave1. Though smaller and slower than earlier Ukrainian maritime drones, its stealth and survivability compensate. An advanced variant reportedly carries a payload approaching 5,000 kilograms of explosives and has been effective in destroying vessels and infrastructure such as the Kerch Bridge. In April 2024, Ukraine announced testing of an uncrewed submarine capable of carrying up to ten divers, six torpedoes or missiles, with 54-hour endurance and speeds reaching 50 kilometers per hour. In May 2024, Northrop Grumman unveiled the Manta Ray, a DARPA-funded drone modeled on the manta ray.

The Commercial and Industrial Expansion

During the 2000s, uncrewed underwater vehicles transitioned from being primarily government testing tools into widely adopted commercial and industrial assets. The number of international users grew substantially, and funding for UUV technology development increased accordingly. This surge in demand pushed the technology beyond the research laboratories and military agencies that had originally driven its creation. Commercial sale of UUVs began in earnest, expanding their application from oceanographic research into broader industrial and commercial contexts. The technological groundwork for this shift had been laid over decades: early screw-propeller thrusters gave way to automatic buoyancy control in more recent models. By the early 2000s, ten different AUV designs had emerged, including screw-driven vehicles, underwater gliders, and bionic AUVs. The Deepglider, one of the most recent models, weighs just 62 kilograms yet can descend to 6,000 meters and travel up to 8,500 kilometers. This dramatic leap in range, depth capability, and reduced mass made UUVs practical for a far wider array of commercial missions than their heavyweight predecessors ever allowed.