In the autumn of 1861, the Navy asked the firm of Neafie & Levy to construct a small submersible ship designed by the French engineer Brutus de Villeroi, who also acted as a supervisor during the first phase of the construction.
The ship was about 30 ft (9 m) long and 6 ft (1.8 m) or 8 ft (2.4 m) in diameter.