The first version of this new submarine was the type VII-A. A chracteristic feature of these new vessels was the trimming tanks attached to the pressure hull to give the submarine good surface stability. By 1936, the demand for greater power and improved steering characteristic as well as more powerful torpedoes had already led to the next type, the VII-B. A consequence of the modifications and improvements to the submarine was that the hull was lengthened by 2 metres. As early as 1938, further modifications had been decided upon, giving rise to the type VII-C. The sub was lengthened by another compartment. This made it possible to increase the size of the control room and conning tower, to further increase the fuel capacity and to improve the diving characteristics.

The first for a type VII-C was placed in 1938. The type VII-C subsequently became the most frequently built German submarine of WWII, it was characterized by robust construction, low diving depth and excellent manoeuvability. This type represents the ultimate high point of the German submarine era.

The main role of the type VII-C was purely as an offensive weapon, designed to carry out sustained disruption of the English supply lines by sinking targeted merchant ships. The plan worked. Allied convoys were attacked by whole packs of German submarines. But by 1943 the page had turned; the hunters became the hunted. The allies had new search equipment such as radar that enabled them to track the German subs known as the "Grey Wolves" mercilessly even by night and in fog. This resulted in heavy losses for the German submarines. Of about 39,000 submariners over 33,000 lost their lives at sea.

The type VII-C like no other illustrates the rise and fall of German submarine during WWII. After a total of 659 of the type VII-C had been built, in 1944 production was discontinued in favour of more modern submarines. One of the best-known type VII-C was the U 552. Built by Blohm and Voss it went into service on 4th December 1940. It became known as the "Red Devil", not only due to the conspicuous painting on its tower, but also because of 15 successful missions against the enemy, 30 ships with a total tonnage of 152,250 GRT were sunk by this sub alone. The first Commander of the U 552 was Erich Topp, one of the most decorated German officers in the Second World War.