Submarines as mobile minefields

The early submarine functioned as a mobile minefield rather than a conventional fleet unit. A boat could wait along a shipping route and attack with torpedoes or surface gunfire, forcing an enemy to treat the area itself as dangerous. Concentrating several boats into a coordinated hunting system required reliable radio communications and command arrangements that were only becoming viable late in World War I. Germany therefore possessed the basic weapon but had little time to exploit the more integrated doctrine that later became associated with wolf packs.