The Type I U-boat was the first post-World War I attempt by the German Kriegsmarine to produce an ocean going submarine. Only two Type IAs were built, but the decision to halt production on further boats is believed to be because of political decisions and not because of major faults in the Type I design. Although the boats did not have any major design faults, they were known to be difficult to handle due to their poor stability and slow dive rate. The type was based on the design of the Finnish Vetehinen class and the Spanish Type E-1, designed by Ingenieurskantoor voor Scheepsbouw (the company also designed the Soviet S class submarine). The design later served as a basis for the development of other types of boats, primarily the VII and IX classes.