Conversion began on three others (U-211, U-263, and U-271) but none was completed and they were eventually returned to duty as standard VIIC attack boats.
Te preinake su otpočele i na još tri podmornice (U-211, U-263 i U-271) ali nijedna nije i dovršena, te su one vraćene u službu kao i tradicionalne VIIC napadačke podmornice.