In 1935, an Italian lieutenant conceived the SLC “Maiale” also known as Il Maiale, the Pig or SLC (Siluri a Lenta Corsa, meaning of Slow Speed Torpedo). During World War II, well-trained Gamma Group together with this secret navel weapon SLC “Maiale” damaged up to 16 naval vessels for a gross tonnage of approximately 200,000 to reverse Italy’s battle disadvantage.

During the World War II (from 1939 to 1945), Panerai was still the official supplier of military instruments to the Royal Italian Navy. On the request of the Italian Navy, Panerai developed underwater instruments like watches and chronographs for navy missions.