Kaidai-type submarineI (海大1型（伊五十一型）, Kaidai-ichi-gata, I-51-class) Kaidai II (海大2型（伊五十二型/伊百五十二型）, Kaidai-ni-gata, I-52/I-152-class) Kaidai IIIa (海大3型a（伊五十三型/伊百五十三型）, Kaidai-san-gata-ē
Type B submarineclasses: Type-B (乙型（伊十五型）, Otsu-gata, I-15-class) Type-B Mod.1 (乙型改一（伊四十型）, Otsu-gata Kai-1, I-40-class) Type-B Mod.2 (乙型改二（伊五十四型）, Otsu-gata Kai-2,