22nd August 1940 Captain Oliver Patch RM flew in a flight of 3 swordfish to sink 4 Italian ships with 3 torpedoes in Bomba Bay.
In July 1940 Italian submarine Iride was chosen for conversion to SLC submarine to attempt the first attack against British naval base in Alexandria.
Work was finished in early August, and on 12 August Iride departed La Spezia and after a brief stop in Trapani on 16 August, reaching the Bay of Menelao in the Gulf of Bomba of the coast of Cyrenaica together with torpedo boat Calipso, which carried the SLC (Human Torpedo) crew, and the support ship Monte Gargano.
Italian Submarines with SLC Tubes
During the night of 21 August the SLC's were loaded onto the submarine's deck, and a test navigation were to be carried out the next morning. A reconnaissance plane flew by in the morning of 22 August 1940 and spotted Italian ships in the bay.
Around noon three Fairey Swordfish torpedo bombers from the aircraft carrier HMS Eagle that were temporarily based at Maaten Baggush airfield in the western desert were launched and attacked Iride and the other ships while they were performing a diving test with four human torpedoes.
At 12.30 they turned inshore into Bomba Bay and opened out to about 200 yards apart. Four miles from shore the submarine was sighted on the surface apparently battery charging. Patch immediately attacked, dropping his torpedo from a height of 3 300 yards.
This hit below the conning tower and the submarine sank in 15m of water. Cheesman and Wenham, both RN, flew on to attack the inshore vessels which proved to be a depot ship and a submarine with a destroyer between them.