The Earliest Concepts of Underwater Travel in Ancient Times
The idea of exploring the depths of the ocean is far older than most people realize. Long before submarines became a reality, ancient civilizations experimented with rudimentary methods to extend human presence beneath the waves. Freedivers in ancient Greece and Rome, for example, used simple tools like weighted stones and hollow reeds to stay underwater for longer periods. These techniques were primarily employed for gathering sponges, pearls, and sunken treasures from shipwrecks—a practice that persisted for centuries.
One of the earliest recorded instances of deliberate underwater observation comes from 332 BCE, during the time of Alexander the Great. According to legend, Alexander himself descended beneath the surface in a crude glass diving bell to observe marine life and inspect submerged defenses. While this account is likely exaggerated, it reflects an early fascination with underwater exploration. The concept of diving bells—air-filled chambers that allowed divers to remain submerged—was later refined during the Renaissance, laying the foundation for future submarine technology.
Beyond practical applications, ancient myths and legends also hinted at the human desire to conquer the underwater world. Stories from various cultures describe submerged cities, aquatic deities, and vessels capable of navigating beneath the sea. Although these early ideas were more fiction than fact, they demonstrate a longstanding curiosity about the ocean’s hidden depths—one that would eventually lead to the invention of the first true submarines.
Cornelis Drebbel—The Man Who Built the First Working Submarine
Cornelis Drebbel, a Dutch polymath born in 1572 in Alkmaar, Netherlands, is credited with constructing the world’s first navigable submarine in 1620. Under the patronage of King James I of England, Drebbel designed a wooden vessel covered in greased leather, capable of submerging beneath the River Thames. His invention was propelled by 12 oarsmen, with oars extending through watertight leather seals, allowing controlled movement underwater. The submarine reportedly reached depths of 12 to 15 feet and remained submerged for up to three hours, an unprecedented feat at the time.
One of Drebbel’s most remarkable innovations was his method for maintaining a breathable atmosphere inside the vessel. He devised a system using air tubes with floating ends to supply fresh oxygen, a rudimentary precursor to modern snorkels. Additionally, historical accounts suggest he experimented with chemical oxygen generation, possibly using saltpeter (potassium nitrate) to refresh the air. While his submarine never saw military adoption, it demonstrated the practicality of underwater navigation, inspiring future advancements in submersible technology.
Drebbel’s contributions extended beyond submarines—he also improved thermometers, developed the first working thermostat, and pioneered optical lens making. Despite his submarine being centuries ahead of its time, his ingenuity laid the groundwork for the evolution of modern underwater vessels.
How Drebbel’s 1620 Submarine Used Oars and Air Tubes to Function
In 1620, Dutch inventor Cornelis Drebbel achieved a remarkable feat: he built the first working submarine, a vessel capable of navigating beneath the water’s surface. Unlike modern submarines powered by advanced propulsion systems, Drebbel’s creation relied on human strength and ingenuity. The craft, constructed with a wooden frame covered in greased leather for waterproofing, was propelled by twelve oarsmen. Each oar extended through leather-sealed openings, allowing movement while preventing water from entering. This rudimentary yet effective design enabled the submarine to travel along the River Thames, submerging to depths of approximately 12 to 15 feet (4–5 meters) between Westminster and Greenwich.
One of Drebbel’s most innovative contributions was his approach to air supply, a critical challenge for prolonged underwater travel. His submarine featured two snorkel-like tubes that extended above the water’s surface, held afloat by small buoys. These tubes allowed fresh air to flow into the vessel, sustaining the crew during submerged operations. Some accounts suggest that Drebbel may have experimented with chemical methods to generate oxygen, possibly using heated saltpeter (potassium nitrate). While his submarine was never adopted for military use, it demonstrated the feasibility of underwater navigation, paving the way for future advancements in submarine technology.
The Turtle—America’s Revolutionary War-Era Submarine
The Turtle was the first military submarine ever used in combat, a daring innovation born out of the American Revolutionary War. Designed in 1775 by David Bushnell, a Yale-educated inventor, this one-man submersible was an audacious attempt to challenge British naval dominance. Its mission? To stealthily attach explosives to British warships, particularly the formidable HMS Eagle, anchored in New York Harbor. Despite its primitive design, the Turtle was a marvel of engineering, demonstrating early concepts that would shape future submarine warfare.
Constructed from oak and reinforced with iron bands, the Turtle resembled two tortoise shells joined together—hence its name. It measured about 7 feet long and could submerge by allowing water into a ballast chamber, resurfacing through a hand-operated pump. Propelled by a hand-cranked screw and equipped with rudimentary navigation controls, the vessel required immense physical effort to operate. However, its greatest limitation was its air supply—restricted to about 30 minutes underwater—forcing the pilot to resurface frequently.
On September 7, 1776, Sergeant Ezra Lee piloted the Turtle in its historic but unsuccessful attack on the HMS Eagle. While attempting to drill into the ship’s hull to attach an explosive charge, Lee encountered an unexpected obstacle: the Eagle’s copper sheathing, which prevented the drill from penetrating. After multiple failed attempts and the looming risk of discovery, Lee was forced to retreat. Though the mission failed, the British were reportedly alarmed by the mysterious underwater threat, marking the beginning of psychological warfare in naval battles.
Despite its setbacks, the Turtle was a groundbreaking achievement. It proved that underwater warfare was possible, inspiring future submarine designs like Robert Fulton’s Nautilus and the Confederate H.L. Hunley. Though it never successfully sank a ship, its legacy as the world’s first combat submarine remains a testament to American ingenuity and military innovation during the Revolutionary War.
How Early Submarines Were Powered Before Modern Engines
Before the advent of modern engines, early submarines relied on a mix of human power, primitive mechanical systems, and experimental propulsion methods. These innovations, while rudimentary by today’s standards, laid the foundation for the sophisticated submersible technology we now take for granted.
The earliest submarines depended entirely on human strength. Cornelis Drebbel’s 1620 submarine, often considered the first working submersible, was propelled by 12 oarsmen who rowed beneath the Thames River. Similarly, the Turtle, a one-man American Revolutionary War-era submarine, used a hand-cranked screw propeller for movement. While effective in short bursts, these methods severely limited speed and endurance.
By the 19th century, inventors began exploring mechanical alternatives. The French Plongeur (1863) introduced compressed air propulsion, eliminating the need for manual labor. Around the same time, Narcís Monturiol’s Ictineo II used a steam engine on the surface and a chemical reaction-based system underwater, marking an early attempt at air-independent propulsion.
The late 19th century saw the rise of electric-powered submarines, such as those designed by Stefan Drzewiecki and Gustave Zédé. John Philip Holland’s designs further refined propulsion by combining gasoline engines for surface travel with electric motors for submerged operation, a concept that evolved into the diesel-electric systems used in World War I and beyond. These early innovations bridged the gap between hand-powered submersibles and the highly advanced nuclear-powered submarines of the modern era.
The Challenges of Early Submarine Designs—Leaks, Air Supply, and Navigation
Designing a functional submarine in the early modern period was nothing short of an engineering nightmare. Unlike today’s sleek, high-tech vessels, early submarines were crude, often experimental machines that faced three fundamental challenges: leaks, air supply, and navigation. Each of these issues posed life-threatening risks to the crew, making underwater travel a perilous endeavor.
Leaks: The Ever-Present Threat
One of the most persistent problems in early submarine design was structural integrity. Many early models, such as William Bourne’s 1578 concept, relied on materials like wood and leather, which were highly susceptible to water damage and leaks. Even Cornelis Drebbel’s 1620 submarine, one of the first functional designs, struggled to maintain a watertight seal despite its greased leather exterior. As submarines attempted to dive deeper, the increasing water pressure would often cause hull breaches, putting the crew at immediate risk of drowning.
Air Supply: A Race Against Suffocation
Oxygen supply was another critical issue. Unlike modern submarines equipped with advanced life-support systems, early designs had no efficient way to replenish breathable air. Drebbel’s submarine introduced a rudimentary method of air replenishment using saltpeter (potassium nitrate) to generate oxygen, but this was far from a perfect solution. Later designs, like Robert Fulton’s Nautilus (1800), attempted to extend underwater endurance by using compressed air tanks, but these only allowed for a few hours of submerged operation. Without a reliable way to maintain oxygen levels, early submariners constantly battled the risk of suffocation.
Navigation: The Blind Leading the Blind
Even if a submarine managed to stay watertight and maintain breathable air, navigating underwater was another daunting challenge. Early submariners lacked sonar, periscopes, or reliable depth-measuring instruments. Drebbel reportedly used a quicksilver (mercury) barometer to estimate depth, but precise control was nearly impossible. Propulsion was also a major limitation—hand-cranked propellers and oars, like those used in the H.L. Hunley (1863), made maneuvering slow and inefficient. Without accurate navigation tools, early submarines were at constant risk of veering off course or colliding with underwater obstacles.
Despite these challenges, early inventors continued to refine submarine technology, gradually overcoming these limitations. Innovations in hull materials, air supply systems, and navigation tools paved the way for the more advanced submarines of the 19th and 20th centuries. Yet, the struggles of these early pioneers highlight just how difficult it was to master the art of underwater travel.
How the First Submarines Paved the Way for Modern Naval Warfare
The idea of underwater warfare seemed like pure fantasy until the first submarines proved their strategic potential. Though early designs were rudimentary, they introduced groundbreaking concepts that reshaped naval combat forever. Cornelis Drebbel’s 1620 submarine, powered by oars and equipped with air tubes, was a pioneering effort that demonstrated the feasibility of underwater navigation (source). While it never saw combat, it laid the foundation for future innovations.
The American Revolutionary War saw the first military deployment of a submarine with David Bushnell’s Turtle in 1776. This hand-powered, one-man vessel attempted to attach explosives to British ships, marking the first instance of underwater offensive tactics (source). Though unsuccessful, it introduced the idea that submarines could be used for stealth attacks. By the 19th century, advancements in propulsion, such as steam-powered designs like the French Plongeur, increased submarines’ viability as military assets (source).
By World War I, submarines were no longer experimental novelties—they were deadly weapons. German U-boats wreaked havoc on Allied shipping, proving that submarines could disrupt supply lines and enforce naval blockades (source). This success led to further technological advancements, including diesel-electric propulsion, periscopes, and sonar systems. These innovations carried into World War II, where submarines played a decisive role in naval strategy. The Cold War then ushered in nuclear-powered submarines, capable of staying submerged for months, fundamentally changing military tactics.
Today, submarines remain a cornerstone of naval warfare, with modern vessels capable of launching ballistic missiles and conducting covert operations. From Drebbel’s wooden craft to nuclear-powered giants like the USS Nautilus, early submarines paved the way for a new era of stealth, endurance, and strategic dominance beneath the waves.
