In the Pacific battles of World War II, much of the publicity and glamour went to the aircraft carriers and the Naval Aviators who flew from them. Yet, as important as the carriers might have been in the major battles that halted Japanese expansion, the most important naval warships in actually prosecuting the war were almost certainly the submarines. In four years of war, American submarines were able to almost completely destroy the Japanese merchant fleet, with the result that Japan was unable to import needed raw materials, or get supplies and replacement personnel to their Pacific garrisons. By the time Truman ordered the atomic bombing of Hiroshima and Nagasaki, Japan had been virtually isolated by the submarine blockade.
World Submarines like the U.S.S. Archer-Fish (SS-311), shown here off San Francisco in June 1945, were the main type used in the Pacific. Archer-Fish was a Balao Class boat—essentially a Gato Class with a thicker pressure hull—and together those two classes made up the largest single type of American submarines.
The technology described in these articles is particularly applicable to the American Fleet-type submarines of World War II, though in a broader sense much of it also applies to both older and more recent types.
Online World Submarine Manual
One of the most interesting World Submarine resources is the collection of manuals that have been made available on the web by the San Francisco Maritime National Park Association. These are absolutely fascinating, and give a very good overview of submarine systems. To read the manuals online, CLICK HERE.