After the conclusion of the African Campaign, with the surrender of the 1ᵃ Army of Messe, the 10 July 1943 the Allies land in Sicily. After defeating the Italian-German troops stationed on the island, the Anglo-American armies cross the Strait of Messina, setting foot in Calabria and beginning the ascent of the peninsula.
Despite the setbacks the morale of the Italian Armed Forces still held: the soldiers of the Royal Army continued to fight, the pilots of the Regia Aeronautica did not stop taking off with the few remaining devices and the Regia Marina was assembling the Fleet waiting for the clash with that ally.
Meanwhile, Supermarina wants to achieve significant success, which can demonstrate the fighting skills of the Regia Marina. The southern Mediterranean is under the total control of the allied naval forces, it is therefore decided to exclude the use of submarines and to once again use the assault vehicles of the Xᵃ Flotilla MAS, again choosing Gibraltar as the target.
The objective of the BG7 operation is to obtain a higher number of hits, both in terms of quality and quantity of ships, compared to the previous BG6 operation.
In early August of the 1943 everything is ready for action: the Rock of Gibraltar's harbor is quite rich in targets, even if well guarded, however the operators and the SLCs of the Decima are ready for the mission: the action would have been taken on the night between the 3 and the 4 August 1943.
Commander Notari and his second Gianoli leave the support ship at 22.53 on August 3 and at 00.15 they reach reach the first group of merchantmen at anchor. The choice falls on a large merchant, probably an American Liberty, with a dead work low on the water, indicating that the ship is fully loaded.
At around 80 meters from the left side of the ship the pig, plunges to the depth of 4 meters, touching the vessel's bottom. The two raiders are able to place the explosive charge under the hull between the two roll fins. Due to the difficulties due to the poor maneuverability of the pig and to the enormous efforts to make it re-emerge, Gianoli and Notari cannot find each other and are forced to leave the separated area.
Notari manages to return to the support ship, while Ginoli is captured by the British security service at the port. However, the deflagration of the charge causes a large gash at the height of the merchant's engine room, causing it to sink.
The other two crews involved in the mission achieve the same results as the first attack: the Cella-Montalenti pair undermines the Norwegian oil tanker Thorshøvdi (photo), from 10.000 tons; Tadini and Mattera apply the charge to the British steamer Stanridge, with a displacement of about 6.000 tons. Both couples are able to return, according to schedule, to the support vessel where they find Notari.
At 4.10, the tanker is blown up Thorshøvdi, which breaks into two sections and sinks. Exactly an hour later, even the steamer Stanridge sinks to the peak, and the same fate touches the type steamer Liberty Harrison Gray Otis.
The BG7 operation was a complete success, and the Allies suffered significant damage, although this had very little influence on the strategic framework of the Mediterranean.
A month later the king accepted the Armistice offered by the Allies, condemning the Regia Marina to an ignominious surrender.
Photo: Imperial War Museum / N. Sørensen