On 19 December, Scirè—at a depth of —released the manned torpedoes from Alexandria commercial harbour, and they entered the naval base when the British opened their defenses to let three of their destroyers pass. There were many difficulties for de la Penne and his crewmate Emilio Bianchi. First, the engine of the torpedo stopped and the two frogmen had to manually push it; then Bianchi had to surface due to problems with the oxygen provider, so that de la Penne had to push the maiale alone to where lay. There he successfully placed the limpet mine, just under the hull of the battleship. However, as they both had to surface, and as Bianchi was hurt, they were discovered and captured. Questioned, both of them kept silent, and they were confined in a compartment aboard Valiant, below the water line, and coincidentally just over the place where the mine had been placed. Fifteen minutes before the explosion, de la Penne asked to meet with Valiants captain Charles Morgan and then told him of the imminent explosion but refused to give further information, so that he was returned to the compartment. When the mine exploded just beneath them, neither was severely injured by the blast, de la Penne only receiving a minor injury to the head from a ship chain. Meanwhile, Marceglia and Schergat had attached their device five feet beneath the battleship 's keel as scheduled. They successfully left the harbour area at 4:30 am, and slipped through Alexandria posing as French sailors. They were captured two days later at Rosetta by the Egyptian police while awaiting rescue by Scirè and handed over to the British. Martellotta and Marino searched in vain for an aircraft carrier purportedly moored at Alexandria, but after some time they decided to attack a large tanker, the 7,554 gross register ton Norwegian Sagona. Marino fixed the mine under the tanker's stern at 02:55. Both divers managed to land unmolested, but were eventually arrested at an Egyptian police checkpoint. In the end, all the divers were made prisoners, though they succeeded in severely damaging both Queen Elizabeth and Valiant, disabling them for nine months and six months respectively. Eight members of Queen Elizabeth's crew were killed. Sagona lost her stern section and the destroyer, one of four alongside her refuelling, was badly damaged. Neither of the two capital ships sank but they were out of action for several months.
Aftermath
This represented a dramatic change of fortunes against the Allies from the strategic point of view during the next six months. The Italian fleet had temporarily wrested naval supremacy in the east-central Mediterranean from the Royal Navy. Valiant was towed to Admiralty Floating Dock 5 on the 21st for temporary repairs and was under repair at Alexandria until April 1942 when she sailed to Durban. By August, she was operating with Force B off Africa in exercises for the defence of East Africa and Battle of Madagascar. Queen Elizabeth was in drydock at Alexandria for temporary repairs until late June, when she sailed for the United States for refit and repairs, which ended the following June. The refit was completed in Britain. Jervis was repaired and operational again by the end of January. Sagona was towed back to England and repairs were not completed until 1946.
In media
The attack is dramatised at the beginning of the film The Silent Enemy. Another movie The Valiant, is about the damage to HMS Valiant in Alexandria harbour. There is also a 1953 Italian movie about the attack.
