LABRADOR SEA
345 MILES DUE SOUTH OF THE GREENLAND COAST
The tip of the shark’s dorsal fin slipped beneath the surface of the frigid water.
Had anyone seen it, they might have thought it odd. The location was approximately nine hundred miles north of where RMS Titanic struck an iceberg and sank in April 1912.
No icebergs were floating around in the area this time of year. Most of the glacial calving on the coast of Greenland happened in the warmer temperatures of late spring and early summer.
Favoring warmer waters where food sources thrived, tiger sharks were frequently found in tropical and subtropical areas like the Caribbean or the Gulf of Mexico. But they were commonly seen in the Pacific waters near Australia, New Zealand, and the islands of the South Pacific. They have also been spotted in the colder waters of the northern Pacific and the Atlantic. Known to live as long as fifty years, these great fish are capable of circumnavigating the globe in the course of their lifespans.
The tiger shark is one of the largest predatory shark species on the planet, just slightly smaller than the more famous great white. They are nomadic animals who mostly follow the warm water currents. Their insatiable hunt for food includes all manner of fish and also giant sea turtles, dolphins, octopi, manta rays, sea birds, sea lions, and even other sharks. Fishermen have split open the stomachs of these ravenous beasts and discovered in whole or in part rats, cats, horses, monkeys, cushions, coats, car tires, and even explosives.
A pelagic species, tiger sharks usually inhabit the deep waters beyond the continental shelf, sometimes over four hundred feet below the surface. Sometimes they venture closer to the coast. They are perfectly designed for long journeys in deep water, and capable of short bursts of speed on the attack.
The largest tiger shark ever caught was just under twenty-four feet in length and weighed nearly seven thousand pounds. Typically, they are half that length and a third that weight.
In overall shape, length, and weight, the average tiger shark is quite similar to the human-designed Mark 48 torpedo.
The Canadian-owned freighter Emerald Glory was a Liberian-flagged vessel. The term of art was “flag of convenience,” which was quite apt. Registering a vessel under the Liberian flag was a legal and convenient way for the owners to avoid the burdensome costs of additional taxes, environmental regulations, union wages, and maintenance requirements that a Canadian flag would have necessitated. This saved the owners over three million dollars per year.
The Emerald Glory had been loaded in the port of Montreal with a variety of cargoes, most of it in containers, but not all. Shipments of forklifts, excavators, gas turbines, plywood, fiberboard, and fuel wood were all bound for Aberdeen, Scotland, and Grimsby-Immingham, on the east coast of England, the busiest port in the UK.
The Emerald Glory was making just over eleven knots on a northerly route in the frigid waters of the Labrador Sea, a decent speed for her aging and fuel-inefficient engines. Her current location, speed, direction, and ports of destination were all broadcast on her AIS and available on a variety of commercial websites.
There were a number of people who monitored her live AIS broadcast, including those who intended to destroy her.
The tiger shark swam at a very low rate of speed, just above that of the eastbound current that carried the Emerald Glory along. The shark was, in fact, exactly in line with the ship as it approached from some two thousand yards away.
This particular shark was more than eighteen feet in length and weighed nearly four thousand pounds, neither of which was particularly unusual for the species.
Had the fish been hauled aboard one of the many fishing trawlers that harvested the fruit of the North Atlantic waters, they would have discovered several differences between this tiger shark and those typical to the species.
The single biggest difference was simply this:
The tiger now diving below the surface of the frigid waters of the Labrador Sea was an autonomous drone.
God—or nature’s god, evolution, depending upon one’s metaphysical orientation—was the world’s greatest designer, and few designs exceeded the hydrodynamic efficiency of the tiger shark.
Biomimicry was widely adopted in many forms of drone technology. Rather than try and reinvent the wheel, the designers of the tiger shark drone let nature be their guide. Whereas actual tiger sharks were designed to hunt for food and reproduce, the tiger shark drone was designed to destroy commercial shipping vessels. This necessitated a few changes in God’s design, not that it needed any improvements in form, only in function.
That function was not unlike the American-designed and -manufactured Mark 48 torpedo, one of the world’s great undersea weapons. A lone sonar-guided, high-speed Mark “fish” was capable of single-handedly destroying a surface or submerged warship.
The latest Mark 48 models weighed about thirty-five hundred pounds including a six-hundred-and-fifty-pound payload of high explosives. Much of the torpedo’s remaining weight was due to the onboard liquid fuel propellant that drove the heavy swash-plate cam engine. The Mark 48’s high-speed, pump-jet propulsion produced speeds exceeding sixty miles per hour underwater. The internal components and high-speed performance necessitated a metal skin and rigid architecture to maintain the torpedo’s structural integrity from launch to impact.
The other requirement for the Mark 48 torpedo system was a delivery platform, which included every submarine class in the U.S. inventory. Delivery platforms like submarines and surface vessels were extraordinarily expensive, complex, large, and heavily crewed.
In short, the brilliant engineers at the U.S. Naval Surface Warfare Center designed the Mark 48 to attain high speeds, dive to great depths, and overcome defensive countermeasures in order to seek and destroy fast-moving, deep-diving enemy subs, their primary targets.
The challenge for the designers of the tiger shark drone was to combine the hydrodynamic efficiencies of the shark with the destructive potential of a torpedo.
While these two design characteristics were seemingly at odds—God versus the Naval Surface Warfare Center—in fact, the solution was relatively straightforward.
The tiger shark drone design variations from the Mark 48 torpedo all stemmed from the variation in targets.
The Mark 48 weapons system was designed for combat against fast, stealthy, deep-diving submarines capable of high-speed defensive maneuvers. This required fast, deep-diving torpedoes with advanced target acquisition capabilities.
But the tiger shark drone targets were slow-moving, non-diving commercial cargo vessels that deployed neither stealth nor any other defensive countermeasures.
That made commercial cargo vessels extremely vulnerable to slow-moving weapon systems like the drone shark.
With that kind of target, the tiger shark drone design solutions immediately suggested themselves.
First and foremost, a slow-moving drone could carry a larger payload—twenty-six hundred pounds of high explosive, four times greater than what the Mark 48 deployed.
Slow-moving targets allowed a slow-moving weapon. This meant the drone required lower energy output and energy use. The battery-powered, electric-motored tiger drone had plenty of both in reserve.
When first described to Sammler, the chief design engineer compared the four-thousand-pound, sixteen-foot tiger drone to a submersible 2020 Tesla Roadster—but with fins instead of tires. The all-electric Tesla Roadster was capable of achieving zero to sixty miles per hour in 1.9 seconds, and could travel over six hundred miles at highway speeds on a single charge of its 200 kWh lithium-ion battery.
But the tiger shark drone wasn’t turning four tires at maximum speed on high-friction asphalt in order to chase down a fast-moving target. In fact, the drone didn’t have to move at all. It could simply drift for hours, if not days, without expending any energy whatsoever as it waited for its target to arrive at the drone shark’s location. Even if it ran continuously at its average speed of thirteen knots per hour, it would still have a range of over twenty-four hundred miles on a single charge. Thanks to its eight-hundred-volt architecture stolen from the Porsche design bureau, it could recharge eighty percent of its capacity in just fifteen minutes.
A particular genius of the tiger shark drone system was its targeting program. In fact, the drone relied on the commercial vessel to target itself—via its own AIS transmissions. Once the target was selected, the tiger drone positioned itself somewhere along the vessel’s path via the drone’s onboard AI program or by remote human operation.
Whereas a conventional submarine and torpedo system had to find and chase an enemy vessel, a deployed tiger drone passively awaited the arrival of its target.
There were many other advantages to the tiger drone design, including its stealth capabilities. Noise, heat, size, wave propagation, and magnetic anomalies were the primary means of detecting submersible and surface vessels. The tiger drone avoided or mitigated all of these.
First, its primary means of propulsion—a swishing tail—produced one-tenth the acoustical noise of a conventional propeller, though the shark had one of these for emergency use or for microbursts of speed.
Second, the tiger drone’s outer hide was comprised of just four millimeters of bubble-infused (“bubble wrap”) latex skin. This dampened sonar signals by as much as ninety-nine percent, and reduced radar wave detection by a factor of ten thousand. A secondary layer of rubber added extra stability and helped shield the few metallic internal components, including its two small and nearly silent electric motors weighing just seventy pounds each.
Third, the skeleton of the fish was comprised of non-metallic polycarbonate “bones” and the propeller shaft and propeller were constructed from German-designed carbon fiber reinforced plastics (CFRP).
Finally, the dorsal fin of the drone served as its antenna, able to send and receive encrypted comms and location signals. It was also able to independently receive and track the AIS signals of any commercial vessel worldwide. And, of course, high-def digital cameras were located behind the clear lenses of the drone’s eyes.
Taken altogether, the tiger drone was practically invisible to sonar, radar, heat, or magnet anomaly detection. But in the extremely unlikely event one of them popped up on screen or scope, the size and shape of the signature would indicate exactly what it appeared to be: a lone shark in the water, not a fast-moving, metal-skinned submarine or torpedo.
Biomimicry at its best.
The research lab that designed the tiger shark drone knew that another significant technical problem still faced them: the delivery platform.
Because of their limited range, Mark 48 torpedoes were delivered to combat areas by submarines and launched from tubes within the vessel.
While the tiger shark had far wider range than a torpedo, it wasn’t capable of completely independent movement. Eventually, its battery would be exhausted, or mechanical issues might arise. And given its slow speed, it would take many days if not weeks to arrive in its zone of operation if launched from its point of origin.
The delivery system option was even more obvious to the designers than the biomimicry “fish” solution for the weapons platform itself.
What better delivery system for a drone fish than a fish trawler?
These “trawler” mother ships were, in fact, converted deepwater fishing vessels, with all of the appropriate gear to pass any unlikely inspection. Modern fishing vessels deployed sonar, radar, navigation, and comms that did double duty as drone support equipment.
In addition, these disguised mother ships possessed both battery recharging platforms for the sharks and drone repair facilities. In the event of an emergency, the sharks could be “caught” by the mother ships, and either towed or brought on board and redeployed elsewhere.
In the unlikely event one of the tiger shark drones was captured by an enemy vessel, the onboard munitions would self-destruct when the machine was lifted vertically unless the gyroscope motion detector was deactivated by its mother ship commander.
There were five mother ship vessels deployed around the world, and each deployed six shark drones. Once deployed in the water, the sharks were given an AIS signal to track. The drone’s onboard computer automatically attacked the vessel in question. The shark drone dove under the hull and exploded, breaking the spine of the ship and destroying its structural integrity with a single but massive charge equivalent to four Mark 48 torpedoes.
Without question, the tiger drone weapon system would have been of limited value in direct confrontation in a wartime scenario with a major seafaring power. But that wasn’t its purpose.
The tiger drone program was a new kind of piracy, operated by a new kind of pirate. Lucrative, yes, but temporarily so. It was a means to an end. Its primary purpose was to distract the United States from an even more dangerous and terrifying operation that had only begun to unfold.
The Emerald Glory broke apart instantly, its two halves sinking in less than seven minutes. Miraculously, three crew members survived the blast. Without lifeboat or vests, they treaded the bone-chilling waters for less than twenty minutes. Each died in turn as their numbing muscles failed. Helpless to avoid slipping beneath the surface, they perished swallowing the sea in whimpering gasps, their corpses blueing in the water as they waited for a rescue that never came.