August 1945 and Post-War
| 6 | August | The first atomic bomb was dropped on Hiroshima. |
| 8 | August | The Soviet Union declared war on Japan. |
| 9 | August | Another atomic bomb was dropped on Nagasaki. |
| 15 | August | Japan capitulated. The Second World War was over. |
On 25 August, Benedetto Brin (T.V. Carlo Imperiali) sailed from Colombo for home, having concluded her series of anti-submarine exercises. She reached Taranto on 22 September.
At the end of the Pacific War, Italian submarines were still participating in anti-submarine exercises. The two former Italian submarines, I–503 (ex-German UIT 24, ex Comandante Alfredo Cappellini) and I-504 (ex-German UIT 25, ex Luigi Torelli), were found in Kobe (Japan). They had the unique distinction of having flown the flags of the three major Axis nations during the war. They were scuttled by the US Navy on 16 April 1946.
In the second half of September, Italian submarines in the Western Hemisphere began concentrating on Bermuda for their final voyage home.
On 20 September, Onice (T.V. Ferdinando Boggetti) sailed from Portsmouth (New Hampshire).
SubDiv 72 having been dissolved, on 24 September, Atropo (T.V. Aredio Galzigna), Speri (T.V. Claudio Celli), and Dandolo (C.C. Leone Monteleoni) sailed from Guantanamo escorted by PC-1192. Speri had a jammed rudder and other defects; they were met by the USS Kiowa (ATF-72), who took Speri in tow for two days; she had to be docked in Bermuda. Two days later, Da Procida (T.V. Francesco Castracane degli Antelminelli) and Vortice (T.V. Giovanni Manunta), escorted by the salvage ship USS Chain (ARS-20), followed from Key West and were joined the following day by Marea (T.V. Attilio M. Russo) from Port Everglades.
On 5 October, the seven submarines accompanied by Chain sailed from Bermuda for Ponta Delgada. Speri was again plagued with engine defects and, from 9 October, had to be towed by the American vessel.
After a four-day stay in the Azores, they left for Gibraltar and reached Taranto on 3 November. The torpedo boats Ariete, Cassiopea, and Libra welcomed them off the port and brought them in.
Delayed by defects, the last submarine, Mameli (T.V. Cesare Buldrini), departed from Key West and reached Taranto on 12 December, towed by the salvage ship USS Escape (ARS-6).
The war was over. For the Italian Submarine Fleet, it had been a gruelling experience; some ninety submarines had been lost in action, and a third of Italian submariners (over 3,000 men) had disappeared with their boats. This was a sacrifice unmatched in other branches of the Italian Armed Forces.
Italian Navy personnel would feel betrayed by the secret terms of the Armistice, which were only revealed after the war when several of their ships were distributed to the victors. Twenty-six submarines had survived the war. They were:
Alagi, Atropo, Bandiera, Brin, Cagni, Corridoni, Da Procida, Dandolo, Diaspro, Galatea, Giada, H.1, Jalea, Mameli, Manara, Marea, Menotti, Nichelio, Onice, Otaria, Platino, Settimo, Speri, Squalo, Vortice and Zoea. In addition, there were eleven midget submarines. Another six submarines were not worth refitting.
Only the submarines Vortice and Giada were kept, and the embryo of the post-war submarine fleet was formed; the others were scrapped by 1948.
In 1946, a referendum abolished the Monarchy, and the King ended his days in Alexandria,[1] the site of the most significant Decima Flottiglia MAS victory. The Regia Marina was no more, but the modern Italian Navy would emerge from its ashes.
[1] Vittorio Emmanuele III died in 1947 and was buried in the Church of Saint Catherine in Alexandria, Egypt. His body was returned to Italy in December 2017.