Leonardo da Vinci was a of the Italian navy during World War II. It operated in the Atlantic from September 1940 until its loss in May 1943, and became the top scoring non-German submarine of the entire war.Clay Blair, Hitler's U-boat War: The Hunters, 1939-1942, p.740The US Navy's most successful submarine, , sank 116,454 GRT, while , the Royal Navy's most successful submarine, sank 93,031 GRT of shipping.

Construction Leonardo da Vinci was built at the CRDA shipyard in Monfalcone, near Trieste, Italy's leading submarine builder. One of six boats of the Marconi class, which were laid down in 1938–39, Leonardo da Vinci was launched in September 1939. Designed as an ocean-going vessel, she was intended for operations in both the Mediterranean and the Atlantic.

Service history With Italy's entry into World War II in June 1940 Leonardo da Vinci was dispatched to the Atlantic to Bordeaux in occupied France to serve in the Italian submarine flotilla there, BETASOM. She arrived October 1940 after a successful transit of the Straits of Gibraltar, scene of a number of Axis submarine losses.

Leonardo da Vinci carried out 11 war patrols, sinking 17 ships of 120,243 GRT,Blair p.739 which included the 21,500-ton ocean liner . Leonardo da Vinci was Italy's most successful submarine in World War II, and her captain, Lt. Gianfranco Gazzana-Priaroggia, Italy's leading submarine ace. In July 1942 Leonardo da Vinci was assigned to a special operation aimed at mounting raids on harbours on the eastern seaboard of the United States. To this end she was converted to carry a , and during the autumn engaged in trials with the new weapon.Kemp p.59-60 However, the operation was delayed due to the need for modifications to the CA craft and Leonardo da Vinci returned to action to the Atlantic.

Planned attack on New York Harbor Leonardo da Vinci was to be used in a clandestine attack on the New York Harbor. The project, first started in July 1942 by Junio Valerio Borghese, involved launching Leonardo da Vinci from the BETASOM base in Bordeaux to the mouth of the Hudson River loaded with a CA-class submarine and a team of divers armed with 28 explosive charges. Once in position, the divers would take the CA-class into the harbor. Their charges – ranging in size from 20 to 100 kg – would be set to undermine the ships in the harbor.

Early tests carried out in August 1942 were promising, showing that Leonardo da Vinci could effectively launch the CA-class and recover it. In reality, however, recovery of the CA-class was a remote possibility, and it was more likely that the divers would have to destroy the vehicle once they had completed setting their charges.

The mission was postponed following the loss of Leonardo da Vinci, and was ultimately canceled when the armistice was signed four months later.

Last patrol In March 1943 Leonardo da Vinci made her last and most successful patrol, to the South Atlantic. On 14 March she sank the Empress of Canada en route to Takoradi, West Africa. She was carrying Italian prisoners of war, and Polish and Greek refugees, and of the 1,800 people on board, 392 perished.Associated Press, “400 Lives Lost In Sinking of Liner Year Ago”, The San Bernardino Daily Sun, San Bernardino, California, Saturday 19 February 1944, Volume 50, page 2. On 19 March Leonardo da Vinci torpedoed and sank the 7,628-ton British cargo ship in the South Atlantic. She captured and took on board one survivor; two other men survived following a 50-day ordeal on a life raft."What Cares the Sea?" by Kenneth Cooke, published by McGraw-Hill, New York, 1960.

In April 1943 Leonardo da Vinci sank four vessels in the Indian Ocean off the coast of Durban.

Fate

After the last sinking at the end of April, Leonardo da Vinci turned for home. On 22 May 1943, off the coast of Spain, her commander unwisely signaled his intention to head for Bordeaux. The submarine's position having been fixed by direction-finding, on 23 May the destroyer and the frigate (both escorts to convoys WS-30 and KMF-15) subjected the submarine to an intense depth charge attack and sank it west of Vigo at an estimated position of . There were no survivors. Jim Wilson, who directed the attack on HMS Ness, was awarded a Distinguished Service Cross for his role.

Successes + Ships sunk by da VinciPatrolDateShipFlagTonnageNotes4th28 June 1941Auris8,030Tanker; 27 survivors from a crew of 596th25 February 1942Cabedello3,557 Freighter; no survivors6th28 February 1942Everasma3,644Freighter from Convoy TAW 12 torpedoed at ; 15 survivors. (See Latvian Mercantile Marine during WWII)7th2 June 1942Reine Marie Stewart1,087 Schooner7th7 June 1942Chile6,956Freighter; 39 survivors from a crew of 447th10 June 1942Alioth5,483Freighter; 8 survivors from a crew of 367th13 June 1942Clan Macquarrie6,471Collier; 1 killed from a crew of 908th2 November 1942Empire Zeal7,009Freighter8th5 November 1942Andreas6,566 Freighter8th10 November 1942Marcus Whitman7,176Liberty ship; no casualties8th11 November 1942Veerhaven5,291Freighter; no casualties9th14 March 194321,517Troopship; 392 killed from 1,800 aboard9th18 March 19437,628Freighter9th17 April 1943Sembilan6,566 Freighter9th18 April 1943Manar8,007Freighter9th21 April 1943John Drayton7,177Liberty ship9th25 April 1943Doryessa8,078Tanker; 11 survivors from a crew of 54Total:120,243

References

Notes

Bibliography Erminio Bagnasco, Submarines of World War Two, Cassell & Co, London. 1977

Paul Kemp : Underwater Warriors (1997) Giorgerini, Giorgio : Uomini sul fondo. Storia del sommergibilismo italiano dalle origini a oggi, Mondadori, 2002, .

External links Leonardo da Vinci at regiamarina.net U-boats off Natal Bill Bizley Leonardo da Vinci (1939) Marina Militare website