One of the special characteristics of naval warfare is its aggressive nature and the speed of its resolution. Unless combat is avoided, naval warfare is invariably swift and decisive. Armies may stand face-to-face for days or months, both up to their shoulders in mud. When warships meet on the high seas, usually one side will soon be celebrating a victory, It is not often that a nation's sea power comes to rest on a single warship, but in the contest between Chile and Peru (1879-1883) this was the case, because this war occurred during the change from wooden ships to ironclads.

Naval strength is customarily measured by counting guns and the weight of the metal they discharge, total tonnage of all combatant ships, thickness of armor plate, and the number of the crews. Before fighting commences this is the only convenient way to assess the strength of opposing forces. But hardware is only one factor of naval power. Once the cannons have been unlimbered an unmeasurable factor can change all calculations, a factor best expressed by the venerable naval maxim: “Men, not ships, win battles.”