Imperial Japanese Navy Type B-1 Submarine. I-15 (1939) and I-37 (1943)

Booklet about the large IJN submarines I-15 and I-37 which were orginally designed as cruiser submarines and embarked a small Yokosuka E14Y1 seaplane launched by catapult. later, the I-37 took Kaiten human torpedos. Many nice 3D drawings as usual !