Submarines are mesmerizing vessels. The opinions of the air dales aside, these are arguably the most important and usable warships in any modern navy now a days. Naval aviation has their own importance , but it only takes one submarine to put a carrier out of existance, and without the carriers the planes don't have any omportance.
From the initial days, the admirals looking to find a way to integrate submarines into their fleet to get competitive and strategic advantage. The idea was to utilize, their ability to dive to let them spy on enemy fleets use them as scouts, and their torpedoes to remove the lighter enemy units from the equation. After that, the battleships would shoot it out and decide the war.
This never happened. Instead, the submarine found its place in the guerre de course, or commerce war. In two wars Germany used their u-boats in a campaign to close the north Atlantic convoy routes, with the intent of isolating Britishers and forcing her to surrender. Germany never succeeded at this, but in the Pacific during World War II the United States, by concentrating its submarine campaign against the Japanese merchant fleet—with the odd opportunistic attack on a warship—actually did succeed in dipping nearly all of the enemy's merchant bottoms.
The articles on this page explain various aspects of submarine technology. Some of these are definitely German, some distinctly American, and some are pertinent to any submarine. (And, just in case anyone isn't aware of it, Unterseeboot (u-boat) is simply the German word for submarine, and not a special term for a particular typeof submarine.
