One Fish, Two Fish, Swordfish, Kingfish
With sea drones already navigating the ocean depths, innovation in AUVs is the wave of the future.

When it comes to unmanned systems technologies, most analysis has focused on aerial innovations, and for good reason – the vast majority of the drones being tested and deployed today hover in the air, at altitudes ranging from a couple of feet to tens of thousands of miles above the earth.
But significant innovation is also taking place far below sea level. The U.S. Navy is developing unmanned underwater vehicles (AUVs), as are university researchers and private companies around the world (including Canadian-based ones), not to mention DIY hobbyists. Some observers have speculated that unmanned naval systems will revolutionize naval operations.
According to the Autonomous Underwater Vehicle Applications Center:
Part of the current effort is the Mk 18 family of unmanned underwater vehicles with side-scan sonar technology and a camera. Mod 1, the Swordfish, is about 80 pounds and 7 inches in diameter. The smaller variant is designed to navigate the surf and beach zones — less than 40 feet of water — which includes the most turbidity of all the water column zones, complicating the UUV’s efforts to determine depth…
The Swordfish has now been joined by the Kingfish, a robot that can gather information underwater for 24 hours. The U.S. Navy used to train dolphins for underwater mine-hunting, but now the mammals are being nosed out by the Kingfish – although dolphins still retain advantages over robots for jobs on the ocean-floor.
Drones are a more humane and cost-effective alternative to dolphins or mine-sweeping ships. When Iran threatened to close the Strait of Hormuz last year if their nuclear weapons program was targeted, the U.S. deployed four mine-sweeping ships. A new Kingfish drone may be introduced to the region next year, which would allow fewer of these ships to be deployed.
The Khaleej Times reported that:
…the Kingfish Mark 18 Model 2 is an upgrade of the first model [the Model 1 Swordfish UUV] and was tested during the recent mine countermeasures drills in the region and came up trumps. It is about 12-feet and resembles a torpedo. Guided by GPS, it also has a WiFi connection and can operate in the shallow waters of the Gulf and search a wide area and map them. There are three Kingfish vehicles in each system. The system can be operated from a rigid-hull inflatable boat, giving naval forces more mobility and speed to locate and detonate mines. . . Another new deployment is the SeaFox mine disposal system. While Kingfish helps to detect mines, the SeaFox drone is sent out to put them out of action. They are being used on ships and MH-53E Sea Dragon helicopters in the Gulf.
You can find a photo of a Kingfish here, and more information on SeaFox and related technologies here.
For those excited by what one sea drone can do, from disarming a mine to detonating a potentially lethal bomb, imagine if you could deploy not just a single KingFish but a whole swarm. Researchers in Germany have moved from the realm of imagination to experimentation, building AUVs that swim together as would a school of fish:
The most important capability a swarm brings AUVs is redundancy. Rather than relying on a singular, expensive platform, MONSUN [a 4 kilogram AUV designed for underwater environmental surveying] uses a handful low-cost, homogenous robots that can alter their role within the swarm. While a portion of the AUVs conduct tasks underwater, the others act as communication relays. If one of these vehicles has a mechanical failure or is lost, the swarm continues to operate.
And so innovation below the surface appears to be taking place at a similarly rapid pace as that above ground, with new models and prototypes continuing to be tested. One impetus may be the argument that as defence budgets shrink, shifting intelligence, surveillance and reconnaissance (ISR) capacities from land-based to sea-based platforms may help cut costs, as the latter would be less vulnerable to attack. Whether the costs of maintaining these platforms will prove prohibitive is unclear, as is whether fueling AUVs will prove an insurmountable obstacle to lengthier missions.