The Invisible had the shape of an elongated ellipsoid of revolution , was 9.14 m long and had a diameter of 1.68 m. The locomotion was carried out by means of belts , three of which were attached to one side and powered by muscle power. For diving it had a ballast tank that could be filled with water for diving. A flexible hose served as a snorkel to supply fresh air. At the bottom there was a metal plate that could be thrown off in an emergency and quickly reappeared. Two sea mines were carried as armament, which were attached to the submarine with chains, could be attached to ships and detonated by means of a time fuse.
The keel was laid in October 1865 and the launch in December of the same year. In January 1866 the submarine was transported to Valparaíso. However, since it was too dangerous to test the submarine while the port was blocked by the Spaniards, it was considered a move to Quintero . But this port has since been bombed by the Spanish. On April 20, 1866, after the Spaniards had withdrawn from Valparaíso, a first test was carried out. The submarine was very unstable in the water and when you were about 11 m submerged, water penetrated. Two of the three pumps failed and so it was very slow to emerge. The Invisible was finally created in the harbor. The next day it was found that the submarine had sunk. Whether it was a technical problem or sabotage remained uncertain.
