U-792 and U-793 were in the first group in this experiment; while U-794 and U-795 were the second experimental group.

These were coastal boats which formed the first production series using the famed Walter turbines but they were still largely experimental boats. The very short range of the Walter system made it more suitable as coastal boats until the unit could be refined. Separate designs were developed for the first group, which was Wa.201 built by Blohm & Voss; and the second group, which was Wk.202 built by Germania Werft.

These boats were quite a bit smaller in size than the first, which was U-791. This first boat had two turbines, but the Wa.201 and Wk.202 boats had just one turbine. There will be additional data on these boats in KTB #116.