The hull was made of cylindrical beams (reinforcement rings) positioned about 520 mm (20.47 in) apart
(Photo Turrini Collection)

R. Smg. Adua in 1941
The cunning tower had already received the necessary modifications to make it less visible and the boat is displaying a new camouflage.
(Photo courtesy Erminio Bagnasco and Achille Rastelli)

The submarine ALAGI in a dry-dock in Messina (Sicily) in 1941.
The picture shows the graceful design of the external hull.
(Photo courtesy Erminio Bagnasco and Achille Rastelli)

The forward diving plane and the anchor of the submarine Adua.
(Photo Turrini Collection)

Crewmembers of the Smg. ARGENTO
(Photo Turrini Collection)

The 100/47 mm deck gun of the Smg. PORFIDO.
(Photo Turrini Collection)