The earliest fighting at sea probably involved no more than exchanges of antipersonnel missile fire with arrows and spears, followed by boarding and hand-to-hand combat with sword and pike. Beginning in about 1000 b.c., galley warships were fitted with an underwater ram, which transformed the hull into a ship-destroying weapon. Boarding, however, remained the main means of reaching a decision. The Greeks later used catapults to launch grapnels and lines to draw enemy ships close enough for boarding. In the third century a.d., the Syracusans invented the corvus (crow), a boarding ramp with a hooked end that held enemy ships in place and provided a bridge that facilitated the attack of infantry. This innovation was used to great effect by the Romans. In the sixth century, the Byzantines developed a flammable liquid (Greek fire) that was squirted at enemy ships and used with deadly effect until the secret of its composition was apparently lost. In the twelfth century, the navy of the Southern Sung dynasty in China deployed armored, paddle-wheel small craft for riverine and canal warfare, and mounted heavy catapults on larger vessels. The advent of gunpowder artillery in the West in the fourteenth century further increased naval missile power. But boarding remained the principal means of winning a large-scale battle fought with galleys up to and including the
Battle of Lepanto in 1571. The function of the corvus in the galleys of this period was assumed by a fixed, iron-tipped structure at the bow (the spur).
By the fifteenth century, European and Chinese sailing warships carried large numbers of light antipersonnel artillery and a few big-guns capable of causing substantial damage to ship structure. In the mid-sixteenth century, the replacement of fixed mountings by moving carriages—an English innovation—allowed guns to be reloaded more rapidly. When such weapons were mounted in numbers, sufficient fire could be generated to inflict substantial damage on an enemy ship and cause many casualties. In 1588, English warships avoided boarding and used their superior artillery to defeat the
Spanish Armada. In 1592, large Korean vessels that were heavily protected by iron armor played an instrumental role in the defeat of an invading Japanese fleet, although their lack of seaworthiness and speed probably accounts for the short life of this innovation before industrialization (see
Yi Sun-Shin). Over the course of the seventeenth and eighteenth centuries, naval ordnance and gunnery remained basically unchanged, although alterations in detail improved performance considerably. By the end of this period, the outcome of naval battles was determined by artillery.
In Europe and the United States, rapid innovation in ordnance followed industrialization. Explosive shells entered general service in Western navies in the 1830s. In the 1850s, the development of new methods of building guns in pieces rather than through whole casting opened the door to the construction of much larger and more powerful ordnance. Rifled ordnance that fired elongated projectiles also appeared at this time. Breech-loading small guns were introduced in the 1870s, breech-loading large guns in the 1880s, quick-firing medium-caliber guns and cordite charges in the late 1880s, more rapid-firing big-guns in the late 1890s, and armor-piercing explosive projectiles and high-explosive shells in the first decade of the twentieth century. Industrial technology also resuscitated old and created new weapons. The adoption of steam power gave vessels greater control over the speed and direction of movement, which revived the ram and otherwise transformed naval tactics, but reduced operational range. Advances in electrical and metallurgical science paved the way for the invention of practicable stationary and mobile underwater explosive devices—that is, the mine and the torpedo. And in turn, new warship types—the torpedo boat, destroyer, and submarine—were developed to serve as launching platforms for the latter device.
In the early twentieth century, the great extension of torpedo range by improved guidance and propulsion mechanisms forced navies to increase the effective range of naval artillery so that surface warships could fight at distances that minimized the torpedo threat. This resulted in the development of a plethora of sophisticated machines—including optical devices such as range finders, calculators that were capable of solving differential equations instantaneously, and complicated electrical data-transmission systems—that improved gun laying and sight setting. These developments in what was known as fire control prompted important changes in capital ship design, such as the all-big-gun battleship and battle cruiser. At the same time, improvements in the submarine and the advent of aircraft increased the potential of underwater and air warfare. The critical importance of the former, the possibilities of the latter, and the limitations of large fleets of surface fighting ships were demonstrated during
World War I, which set the stage for the major developments of the 1920s and 1930s.
During the two decades between the world wars, the offensive capabilities of large surface warships were greatly increased by improvements in guns, associated mechanisms, fire control equipment, communications, and auxiliary aircraft; their defensive qualities were enhanced by antisubmarine sensors and weapons such as sonar and depth charges, and antiaircraft sensors and weapons such as radar, fire control analog computers, fuse-setters, dual-purpose (surface and antiaircraft) medium artillery, and rapid-firing light cannon. On the other hand, the advent of the aircraft carrier and improvements in the speed, range, and payload of aircraft during the same period produced a weapons system whose potency rivaled that of the surface capital ship. And the power of submarines was also multiplied by the development of sophisticated analog computers that aimed gyroscopically guided torpedoes, improved engines and hull design, and more effective communications. As a consequence, by the outbreak of
World War II, all major navies were well on the road to the creation of forces that combined surface, underwater, and air elements, or "balanced fleets."
During World War II, advances in aircraft, among other things, tipped the scales in favor of the aircraft carrier over the battleship as the principal weapon of major navies. The advent of nuclear bombs then gave navies the capacity to devastate targets on land as well as at sea through aircraft strikes from carriers, or ballistic or cruise missiles launched from submarines. Air defense was vastly improved by the invention of guided missiles and various forms of electronic countermeasures. Nuclear propulsion allowed the construction of major warships with virtually unlimited operational range, which in particular enhanced the fighting capability of submarines. Advances in sensors and communications, and the concomitant development of bureaucratized information management (the combat information center) and electronic data processing, gave groups of warships and supporting air and space power unprecedented ability to cooperate and to coordinate their use of a variety of air, surface, and underwater weapons. The advent of highly compact digital computers also made it possible to replace voluminous files of paper on board ship with much smaller and lighter installations, freeing space for other purposes while improving the efficiency of administration and engineering maintenance.