Prior to the outbreak of WWII the Japanese began construction of several different types of midget submarines. Recognizing the strategic importance of such a weapon for combat use, Japan built hundreds of these "mini subs" ranging in size from just under 80 ft. to over 100 ft. Designed to carry a crew of 2 to 3 sailors and armed with two torpedoes, these small subs were originally intended to be transported on ships and deployed in the path of an enemy fleet. However, very quickly the Japanese saw the advantages of using the mini subs for special operations inside enemy harbors where conventional submarines could not go. To enhance their stealth capability, the midget subs were modified to ride atop full size subs and be deployed at sea near the target location.