training mission off the western coast of Sardinia following the completion of the conversion procedure. On April 29, 1942, Ambra left La Spezia to conduct an operation against the naval base at Alexandria. After reviewing the aerophotographs of the port of Alexandria it was realized that the British battleships and were severely damaged by the SLC attack on December 18, but not sunk. It was therefore decided to launch a new SLC attack against Alexandria: the designated targets were and the submarine depot ship . On May 5, 1942, Ambra arrived at Leros and embarked SLC and their crews. On May 9 (or 12) 1942 Ambra left Leros to her designated area where she arrived in the evening of May 14, 1942, in view of Alexandria's harbor. At 20:50 three SLCs were released and headed for the port. However, due to existing currents, Ambra drifted while the preparation were under way, and released SLC units in the wrong place. As a result, SLC units wandered along the coast looking for port access, and couldn't locate it. Running out of fuel or due to malfunctions, all three SLC units sank, and the mission was a complete failure. Meanwhile, at 21:05 Ambra left the area and headed back to the base. On May 24, 1942, she reached La Spezia. This was the last operation against Alexandria not only because of the failure, but also because following the Italian-German advance in Egypt, most Mediterranean Fleet ships were transferred to Palestine or to the Red Sea. Following defeat in the Second Battle of El Alamein and Operation Torch, the German-Italian position in North Africa became untenable. With Algeria switching sides from Vichy to Free France side, Allies gain a valuable port in Algiers. Decima Flottiglia MAS was ordered to organize a raid on the harbor of Algiers since it was teeming with all possible kind of vessels. Ambra sailed from La Spezia in the early afternoon of December 4, 1942. She reached the coast of Algeria in the evening of December 7, but adverse weather conditions forced her to remain inactive for several days. Finally, on December 11 the weather improved and Ambra started approaching Algiers. Due to strong aircraft presence, an approach had to be made at a great depth. Captain Arillo managed to penetrate the harbor by moving close to the bottom, and at 19:40 he reached the harbor at the depth