After its annexation of Ethiopia, the Italian government for unknown reasons decided to reduce its land and nary forces. Two naval officers, Elias Toschi and Teseo Tesei, however, received official approval from the Supermarine headquarters in Rome to continue with the development on the famous Mignatta used by Paolucci and Rossetti toward the end of World War I.

Escon.d in the La Spezia Naval Base, the two men produced a new type of weapon, a prototype of a 22-foot torpedo powered by electricity and controlled by one or two frogmen who would sit astride its body to direct ft Here's how Toschi described it:

"At night, under cover of darkness and steering by luminous control instruments, [two men would] be able to aim at and attack their objective while remaining quite invisible to the enemy."

"The operators, unhampered by the steel structure, are free to move and act at will, to reach the bottom of the sea and travel along it in any way and direction, and are able to cut nets and remove obstacles with special compressed-air tools and, therefore, reach any target."