May 19, 2025: The American DARPA research agency has developed something old but with a new twist. They have built a 55 meter long, 250 t0n naval drone, otherwise known as an autonomous ship. This required five years of development effort. The navy plans to use these drones for reconnaissance and surveillance or as warships. When armed, their anti-ship, anti-aircraft or land attack missiles from Vertical Launch System, or VLS cells, are in a cargo container secured to the deck of the drone ship. Fire control officers on other warships, or operating from a land base, control the use of these missiles. Logistics is another matter. These drone ships have to be rearmed and refueled, Refueling could be handled using air-to-air refueling technology. A drone tanker ship could refuel a drone combat ship at sea. Replacing the weapons containers would be more difficult and could be done at sea from manned ships. Otherwise it would be done dockside in a port or the well deck of a navy amphibious ship.

The DARPA drone is not the first. The island state of Singapore developed and built MARSEC naval drones. These 30-ton drones are 16.9 meters long with a top speed of nearly 50 kilometers an hour and endurance is up to 40 hours at sea.

The U.S. Navy has also been seeking ways to learn from the Ukrainian use of naval drones. These drones defeated the Russian Black Sea Fleet, destroying at least a dozen warships. The remnants of the Black Sea Russian fleet have fled to ports over a thousand kilometers from operating Ukrainian ports. Initially Ukraine had only surface-to-ship missiles when the war started. Ukraine eventually shifted to three new naval drones, Sea Baby, Mother, and MAGURA, or Maritime Autonomous Guard Unmanned Robotic Apparatus.

Some of these naval drones were used for a mid-2023 Kerch Bridge attack. One of the drones varied 850 kg of explosives and inflicted enough damage to halt use of the bridge. The Mother drone carried 450 kg and MAGURA 320 kg. In addition to attacking targets, these drones can also be used for reconnaissance and surveillance using video cameras that broadcast what they see back to the drone operator. Some drones have been armed with small rocket launchers, or even anti-aircraft missiles, and one of those shot down a Russian fighter-bomber. The Mother drone has a range of over 700 kilometers and can operate on the high seas. Endurance is about 60 hours, and top speed is over 70 kilometers an hour. MAGURA has similar characteristics. Mother was used for an attack on the Russian naval base at Novorossiysk, which is a thousand kilometers from Crimea.

Ukraine has been developing subsurface drones and in early 2023 the first one, the Toloka2 TK-150 was introduced. This drone was 2.5 meters long and equipped with a sensor mast that remained above the surface for navigation and to identify targets. Toloka2 can also carry a small explosive warhead. Later, Ukraine developed the larger Marichka drone that is 6 meters long and one meter in diameter. Ukraine has planned for a Western manufacturer to build and weaponize Ukrainian drones.

Ukrainian drones have been quite successful in attacking and sinking or disabling Russian navy ships. So far there have been over a dozen attacks which resulted in sinking or damaging about twenty ships. The presence and aggressive use of the drones meant that Ukraine’s grain corridor was kept open despite Russia’s threats to interfere. Beyond symbolic significance, the corridor holds critical economic importance for Ukraine and is expected to contribute up to seven percent to GDP growth in 2024 because of the grain shipments.

Russian countermeasures to Ukrainian naval drones included using aircraft and helicopters to destroy slow-moving drones before they attack, and expanding use of jamming to disrupt drone control signals. These changes made it much more difficult for Ukrainian naval drones to reach and destroy targets. But by 2025 the Russians had already lost control of the Black Sea and were not getting it back.

This leaves Russian warships dependent on bases in the north, near the land border with Norway, and in the Far East, near Japanese and South Korean naval bases. In a post-Cold War development the Japanese and South Korean fleets are now far larger than the Russian Far East fleet. Before the 1990s, the South Korea fleet was largely non-existent and the Japanese fleet tiny and purely defensive. Chinese naval power began to emerge by the late 1990s but took another decade to become a significant force. Then as now, the American West Pacific fleet was a major naval power in the region.

The lessons learned by American, Chinese, Taiwanese, Ukrainian and Russian naval commanders is that these drones have changed the rules for naval warfare. If China tries to invade Taiwan, they have to prepare countermeasures for numerous naval drones blocking the way. Everyone continues to observe Black Sea operations for details on what new tactics, techniques and drones designs appear. The U.S. has an edge because they are a major supporter of Ukraine and are seeking to make the most of their insider knowledge of the Ukrainian naval drone effort.