In the storied history of naval warfare, the submarine occupies a special place. It is to war on sea what the airplane is to land war: Liberated from the handicaps of purely surface operation, both submarines and airplanes can roam the world freely, delivering devastating strikes across vast distances while confuting enemies with their speed, stealth, and versatility.
Attempts to design submarines go back at least as far as the fifteenth century, but serious efforts to build them began only in the early nineteenth century. The technological problems to overcome were staggering: adjustable buoyancy, underwater propulsion systems, vessel stabilization, air supply, and weapon launching systems. During the Civil War, a hand-powered Confederate vessel became the first submarine to sink an enemy warship; however, it simultaneously became the first to sink in action. It was not until the 1890’s that submarines emerged as practical warships. Over the next two decades (as airplanes were being developed), submarines began entering navies, but few naval experts took the submarine seriously. To many, it seemed to be a weapon for the weak—a sneaky device that no self-respecting navy would employ. With the onset of World War I, however, German U-boats took little time transforming the submarine into one of the most effective and feared weapons in warfare.
The full history of submarines is told in fascinating and authoritative detail in Dan van der Vat’s sixth book on modern naval history. The sea lion’s share of attention goes to the two world wars, but long chapters on the earlier and later eras are equally fascinating.