Dolphins, sea lions, and beluga whales have all been deployed in military conflicts, with programs dating back to 1959. The most extensive effort is the U.S. Navy Marine Mammal Program, which has trained animals to detect underwater mines, guard ships against enemy divers, and recover lost military hardware from the ocean floor. The Soviet Union ran parallel programs, and evidence suggests Russia continues this work today.
Why Militaries Turned to Marine Animals
The ocean is a difficult place for technology. Most long-range military sonar uses long wavelength pulses that can’t distinguish a buried mine from an old shell casing. Dolphins, by contrast, produce brief clicks composed of a broad range of short wavelength sounds that can precisely probe the shape of a buried object by bouncing off its contours and crevices. Longer wavelengths give a blurrier picture. Engineers have tried to replicate this ability with artificial sonar systems, but dolphin biosonar remains superior for certain tasks, particularly identifying objects buried in sediment or resting on cluttered seafloors.
Dolphins can detect targets over 650 meters away using specialized click patterns. When searching for something distant, they produce coded bursts of clicks that function like a matched filter, helping them pick out echoes from background ocean noise. No machine replicates this combination of range, precision, and adaptability in shallow coastal waters where mines are most dangerous.
Bottlenose Dolphins: Mine Hunters and Port Guards
The U.S. Navy began testing marine mammals in 1959. In the early years, more than a dozen species were evaluated, including sharks, rays, sea turtles, and marine birds. Most were eventually ruled out. Today the program relies on just two species, and the bottlenose dolphin handles the most complex work.
Dolphins serve two primary roles. The first is mine detection. A dolphin swims through an area, locates a mine or suspicious object on the seafloor, then returns to its handler’s boat and signals what it found. Handlers deploy a marker at the location so human divers or robots can neutralize the device. The dolphin never touches the mine itself.
The second role is swimmer detection. During both the Vietnam War and the Persian Gulf conflicts, dolphins were used to protect Navy vessels at anchor from enemy swimmers trying to plant explosives on ship hulls. When a dolphin detects an intruder, it returns to its handler and gives a trained response. The dolphin can then be sent back to “tag” the swimmer with a marker device so Navy personnel can locate and apprehend them.
During the Vietnam War, rumors circulated about a “swimmer nullification program” in which dolphins were trained to kill enemy divers using a device similar to the tagging mechanism. The Navy has consistently denied this, stating that no dolphin has ever been trained to attack a human. The program was classified for decades, which fueled speculation. It was declassified in the early 1990s, and the Navy has since shared details openly, though the old rumors persist.
California Sea Lions: Deep-Water Retrievers
California sea lions fill a different niche. Their excellent underwater vision (even in murky or low-light conditions) and diving ability make them ideal for locating and recovering objects on the ocean floor. Under a program called Project Quick Find, sea lions demonstrated the ability to locate and recover objects equipped with acoustic pingers from depths of 500 feet. One animal consistently performed simulated recoveries at that depth, while others succeeded at 420 feet.
The practical application centers on recovering lost military hardware. The program focused on practice torpedoes, experimental mines, and test weapons that would otherwise require human divers or expensive submersibles to retrieve. In an operational demonstration, a sea lion successfully recovered an anti-submarine depth charge from 180 feet of water. The recovery device the animal carried could grip objects up to 12 inches in diameter and handle weights up to 2,000 pounds, meaning the sea lion only needed to attach the grabber before the object was winched to the surface.
Sea lions also assist with swimmer detection, similar to dolphins. Their speed and agility underwater allow them to approach and tag an intruder, attaching a clamp connected to a line that handlers on the surface can use to pull the swimmer in.
Beluga Whales: Cold-Water Operatives
The U.S. Navy explored using beluga whales because they offered something dolphins and sea lions couldn’t: the ability to operate in frigid Arctic waters and dive to much greater depths. Like dolphins, belugas use sonar to navigate and can produce the same kind of sophisticated click patterns useful for identifying underwater objects. Their thick blubber and Arctic adaptations made them candidates for operations in environments where bottlenose dolphins simply couldn’t function.
The Soviet Union also trained belugas, and evidence of Russia’s continued interest surfaced dramatically in April 2019. A beluga whale appeared off the coast of Norway wearing a tight harness fitted with camera mounts. The clips on the harness were stamped “Equipment St. Petersburg.” The whale, quickly nicknamed Hvaldimir (a combination of the Norwegian word for whale and the name Vladimir), was found roughly 250 miles from Murmansk, home to several Russian naval bases. Marine biologists believe Hvaldimir likely escaped from a Russian military facility where he performed tasks such as guarding naval ports and searching for mines.
Hvaldimir’s discovery confirmed what Western intelligence agencies had long suspected: that Russia maintained active military marine mammal programs, likely inherited from Soviet-era facilities. The Soviet Union had operated a major dolphin training center in Sevastopol, Crimea. After the Soviet collapse, Ukraine took control of the facility and eventually repurposed the dolphins for therapeutic work with autistic and emotionally disturbed children. When Russia annexed Crimea in 2014, reports indicated the military dolphin program was reactivated.
Other Species That Were Tested
The Navy’s early experimentation cast a wide net. Sharks were evaluated for their electroreceptive abilities, which allow them to detect the faint electrical fields generated by metal objects and living organisms. Rays were studied for similar reasons. Sea turtles were tested for their long-range navigation capabilities, and marine birds were assessed for potential surveillance roles. None of these species proved trainable or reliable enough for operational deployment, which is why the program narrowed to dolphins and sea lions.
How These Animals Are Protected
Military use of marine mammals in the United States falls under the Marine Mammal Protection Act, which requires the Navy to implement measures that produce the “least practicable adverse impact” on the animals. For military readiness activities, this standard is balanced against personnel safety, practicality, and the effectiveness of the mission.
All bridge watch personnel, commanding officers, patrol aircraft crews, and lookouts must complete Marine Species Awareness Training before standing watch. Vessels must maintain buffer zones of 500 yards around whales and 200 yards around other marine mammals during operations. When large whale groups of four or more are spotted near Navy vessels in certain areas, real-time alerts are issued to all ships in the vicinity. The Navy also issues seasonal awareness messages timed to whale migration patterns and oceanographic conditions.
The animals in the program itself receive veterinary care, and the Navy has stated that its dolphins and sea lions are never placed in situations where they could be harmed by mines or hostile swimmers. The animals detect and report threats but do not interact with them directly. Whether these protections are sufficient remains a point of debate among animal welfare organizations, particularly given that the animals are deployed in active conflict zones where conditions are unpredictable.