Italian submarines in World War Two


Diaspro (DS)
Diaspro

TypeCoastal / Sea going 
ClassPerla (22) 
Laid down 21 Sep 1935 Cantieri Riuniti dell'Adriatico, Monfalcone
Launched5 Jul 1936
Commissioned22 Aug 1936
End service
Stricken1 Feb 1948
Loss date
Loss position
History Stricken 1-2-1948
Fate

Commands

CommanderDate fromDate toCommand
C.C. Oderisio Maresca23 May 194011 Jun 1940
T.V. Luigi Bonatti11 Jun 194023 Jun 1940
T.V. Marino Salvatori23 Jun 194018 Dec 1940
T.V. Rodolfo Bombig19 Dec 194029 Dec 1940
C.C. Junio Valerio Borghese29 Dec 194012 Feb 1941
T.V. Antonio Dotta13 Feb 194130 Nov 1942
T.V. Alberto Donato30 Nov 19425 Sep 1943
T.V. Emilio Botta12 Sep 194322 Nov 1944
T.V. Giovanni Tarabini Castellani22 Nov 1944Aug 1945

Patrols and events

 CommanderDateTimePortArr. dateArr. timeArr. portMilesDescription
Maresca, Oderisio5 Jun 19400402Monfalcone5 Jun 19401040Pola64Passage Monfalcone-Pola.

Maresca, Oderisio8 Jun 19400310Pola8 Jun 19401655Fiume66Passage Pola-Fiume.

Maresca, Oderisio10 Jun 19400310Fiume10 Jun 19401655Fiume7Exercises.

Bonatti, Luigi12 Jun 19402203Fiume17 Jun 19400907Naples1080,5Passage Fiume-Naples.

Bonatti, Luigi18 Jun 19401128Naples18 Jun 19401155Naples1Changed anchorage.

Bonatti, Luigi19 Jun 19400900Naples19 Jun 19401704Castellammare di Stabia32Exercises.

Bonatti, Luigi20 Jun 19400820Naples20 Jun 19401655Castellammare di Stabia35Exercises.

Salvatori, Marino23 Jun 19400830Castellammare di Stabia23 Jun 19401700Castellammare di Stabia25,5Exercises.

Salvatori, Marino25 Jun 19400800Castellammare di Stabia25 Jun 19401600Castellammare di Stabia18Exercises.

Salvatori, Marino27 Jun 19400900Castellammare di Stabia28 Jun 19401247La Maddalena230Passage Castellammare di Stabia-La Maddalena.

Salvatori, Marino28 Jun 19401453La Maddalena28 Jun 19401653La Maddalena2Changed anchorage.

1Salvatori, Marino3 Jul 19401413La Maddalena6 Jul 19401932La Maddalena541Patrolled off La Galite in 37°47'N, 08°51'E on a 45°-225° axis, on a patrol line with Neghelli and Scirè. Uneventful.

2Salvatori, Marino10 Jul 19400040La Maddalena12 Jul 19400450La Maddalena180Patrolled in 310° - 125 miles (or 38 miles?) from Asinara Point. Sailed with Argo, Scirè and Iride to form a patrol line.

Salvatori, Marino16 Jul 19401352La Maddalena16 Jul 19402012La Maddalena32Exercises.

Salvatori, Marino23 Jul 19400820La Maddalena23 Jul 19401030La MaddalenaDocked.

Salvatori, Marino25 Jul 19401220La Maddalena25 Jul 19401240La MaddalenaUndocked.

Salvatori, Marino30 Jul 19401750La Maddalena31 Jul 19401014Cagliari160Passage La Maddalena-Cagliari.

3Salvatori, Marino1 Aug 19400220Cagliari11 Aug 19401543La Maddalena1236Patrolled north of Cape Bougaroni on a line from 38°10'N, 06°30'E and 05°20'E, on a patrol line with Axum, Medusa and Turchese. The object was to intercept an enemy force from Gibraltar. Uneventful.

Salvatori, Marino24 Aug 19400800La Maddalena24 Aug 19401730La Maddalena53Exercises.

4Salvatori, Marino30 Aug 19402250La Maddalena4 Sep 19402200La Maddalena753Patrolled north of Cape Bougaroni on parallel from 38°20'N, 09°00'E to 06°00'E on a patrol line with Axum, Alagi and Medusa.
  1 Sep 19400610
0720 (e)
At 0610 hours, a Sunderland was sighted at a short distance coming head on. It passed Diaspro on the starboard side and T.V. Marino Salvatori ordered the submarine to dive. As she did so, the aircraft made a stern attack, strafing her. The submarine reached a depth of 40-50 metres and proceed westward.

At 0740 hours, five bombs were heard, one of them loudly ahead, the others more distant on both sides. Corallo went down to 70-80 metres. Hydrophone noises were heard and the submarine moved away from them. At 0854 hours, an explosion was heard. At 1035 hours, five explosions were heard astern. At 1220 hours, three explosions was heard to starboard. At 1707 hours, a bomb was heard ahead and finally at 1725 hours five bombs were heard astern.

The attacking aircraft was a Swordfish from the aircraft carrier HMS Ark Royal.

Salvatori, Marino26 Sep 19401008La Maddalena27 Sep 19401235Cagliari176Passage La Maddalena-Cagliari.

Salvatori, Marino7 Nov 19400750Cagliari7 Nov 19401225Cagliari?Exercises.

5Salvatori, Marino9 Nov 19401835Cagliari12 Nov 19401907Cagliari443Patrolled in 315° - La Galite - 20 miles, with night patrol as far as 120 miles to the west, on a patrol line with Medusa, Aradam, Axum and Alagi. Sighted only a French convoy at 0800 hours on the 10th.

6Salvatori, Marino15 Nov 19401841Cagliari19 Nov 19401541Cagliari542Patrolled north of Cape Bougaroni on parallel from 37°20'N, 06°00'E to 05°00'E.
  17 Nov 19401030
(0) North of Cape Bougaroni.
At 1030 hours, a British destroyer of the "H" class was sighted at a distance of 7,000 metres, steering 080°, 12 knots. Diaspro could not close the range for an attack.

7Salvatori, Marino26 Nov 19400138Cagliari2 Dec 19401353Cagliari702Patrolled southwest of Sardinia, from 38°20'N, 08°40'E to 10 miles south, on a patrol line with Axum, Aradam and Alagi.

Bombig, Rodolfo19 Dec 1940Cagliari29 Dec 1940Cagliari702At Cagliari. Change in command.

Borghese, Junio Valerio13 Jan 19410935Cagliari13 Jan 19411110Cagliari1,5Trials?

8Borghese, Junio Valerio21 Jan 19411525Cagliari22 Jan 19412335Cagliari201,7Patrolled south of Sardinia to replace Corallo who had to interrupt her mission because of defects. Early return because Diaspro also had defects.

9Borghese, Junio Valerio9 Feb 19410057Cagliari11 Feb 19411226Cagliari294,5Patrolled east of La Galite from 37°30'N, 09°50'E to 20 miles northward. Borghese was criticised by Rear-Admiral Oliva for submerging from 2400 hours to 0155 hours on the 10th and ignoring instructions issued on 20th January to Mediterranean submarines to operate on the surface during dark hours for at least the first 15 minutes of each hour.

Dotta, Antonio14 Feb 19410829Cagliari14 Feb 19411215Cagliari28,5Exercises.

Dotta, Antonio6 Mar 19410010Cagliari7 Mar 19410830Naples271Passage Cagliari-Naples.

Dotta, Antonio18 Apr 19410911Naples18 Apr 19411841Naples52Exercises.

Dotta, Antonio21 Apr 19410825Naples21 Apr 19411148Naples35Exercises.

Dotta, Antonio23 Apr 19410800Naples23 Apr 19411811Naples46Exercises.

Dotta, Antonio28 Apr 19410948Naples28 Apr 19411705Naples39Exercises.

Dotta, Antonio30 Apr 19410835Naples30 Apr 19411255Naples29Exercises.

Dotta, Antonio2 May 19410837Naples2 May 19411407Naples26Exercises.

Dotta, Antonio6 May 19411940Naples7 May 19410050Naples30Exercises.

Dotta, Antonio12 May 19410810Naples13 May 19411810Cagliari300Passage Naples-Cagliari.

10Dotta, Antonio21 May 19410440Cagliari23 May 19411120Cagliari314Patrolled east of La Galite in 37°40'N, 09°50'E, with Corallo in an adjacent area, to intercept Force H reported to have sailed from Gibraltar. Uneventful. Sighted only an aircraft and heard H.E.

11Dotta, Antonio5 Jun 19412315Cagliari12 Jun 19411150Cagliari824,5Patrolled in Western Mediterranean from 37°54'N, 08°00'E on course 265° to 06°00' then (between Sardinia and Bone) against an expected convoy from Gibraltar. Uneventful.

12Dotta, Antonio2 Jul 19412119Cagliari12 Jul 19411200Cagliari991,5Patrolled in Western Mediterranean within 20 miles from 37°20'N, 02°40'E, with Corallo in an adjacent area, against an expected force from Gibraltar Uneventful.

13Dotta, Antonio16 Jul 19411725Cagliari19 Jul 19410805Cagliari429,5Patrolled in Western Mediterranean on parallel between 37°30'N and 37°40'N, 06°00'E to 05°00'E, with Alagi in an adjacent area, against an expected force from Gibraltar. Uneventful.

14Dotta, Antonio21 Jul 19411458Cagliari24 Jul 19410745Cagliari352Patrolled off Cape Bougaroni, on parallel from 37°30'N, 06°00'E to 05°00'E, with Alagi in an adjacent area. All torpedoes expended.
  22 Jul 19412307
2310 (e)
38° 10'N, 5° 30'EAt 1005 hours, as Cape Bougaroni was in sight, information was received that, at 0850 hours, an aircraft had spotted a large naval force in 38°26' N, 03°25' E.

At 1130 hours, a signal from MARICOSOM revealed that a force of one battleship, one aircraft carrier and four destroyers had been sighted at 0920 hours in 38°26' N, 03°35' E, steering 090° at 18 knots. T.V. Antonio Dotta estimated that this force could be 45 miles north of his position, at 1630 hours. He immediately altered course, expecting to reach the interception course at 1600 hours.

At 1440 hours, as Diaspro was proceeding northward, an order from MARICOSOM gave her freedom of action to move outside her patrol area to intercept the enemy.

At 1920 hours, a new signal from MARICOSOM reported the enemy's position at 1545 hours as 75 miles north of Cape Bougaroni, steering 090° at 20 knots. It was now described as one battleship, one aircraft carrier and seven destroyers. However, this position was only 7 miles from Diaspro at 1545 hours and, since no hydrophone noises had been picked up, Dotta estimated that the position provided by MARICOSOM was erroneous. At 1950 hours, bomb explosions could be heard to the west.

At 2015 hours, Diaspro was informed by MARICOSOM that an enemy naval force had been reported at 1505 hours, 75 miles north of Cape Sigli, consisting of a battleship, an aircraft carrier, four cruisers and five destroyers. It was not clear if this was the same force or a different one. At 2200 hours, the submarine submerged briefly to listen with the hydrophones and detected numerous noises westward. All forward tubes were readied as Corallo proceeded on the surface.

At 2258 hours, shadows were sighted and, two minutes later, the diesels were stopped and the electric motors switched on for a silent approach.

At 2304 hours, a naval force of eight to ten ships was sighted in the process of reverting course from 090° to 270°. It could now be identified as one or two destroyers leading the formation, followed by four cruisers, other destroyers, a battleship, an aircraft carrier and one or two destroyers bringing up the rear. The speed was estimated at 10 knots and distances varied from 1,000 to 1,300 metres.

At 2307 hours, a full salvo of four torpedoes was fired from the bow tubes aimed at the cruisers. They missed. T.V. Dotta believed that the very visible phosphorescence of the torpedo tracks had enabled the enemy to take avoiding action.

At 2309 hours, Diaspro had reverted course to fire two stern torpedoes aimed at the battleship and aircraft carrier from 700 metres and then crash-dived. Two explosions were heard about a minute after firing leading Dotta to believe that he had scored one or perhaps both the major units.

This was Force H covering the SUBSTANCE convoy, with the battle cruiser HMS Renown, the battleship HMS Nelson, the light cruiser HMS Hermione, the aircraft carrier HMS Ark Royal and screened by destroyers. One of these destroyers, HMAS Nestor, stationed on the starboard wing, reported two torpedoes, which were avoided. Just prior to this, two explosions had been heard which were probably torpedoes from Diaspro's first salvo, either detonating prematurely or hitting the sea bed. The destroyer now obtained an ASDIC contact at 1,700 yards and dropped a pattern of five depth charges set at medium depth, which exploded as the submarine had reached a depth of 40 metres. Another pattern of six depth charges was dropped on a second run and the same number on a third run. Nothing was seen, but there was a strong smell of oil.

In the submarine, about thirty depth charges were heard from 2312 to 0050 hours on 23rd July. Although, the first pattern was close, the remainder were not and the submarine was only slightly damaged. Diaspro had dropped to a depth of 138 metres before stabilising at 116 metres.

At 0330 hours, she made an enemy report and at 0557 hours sighted a squadron of destroyers apparently hunting her. Diaspro dived and proceeded to Cagliari. This is one of the rare instances, when an Italian submarine returned from a patrol in the Mediterranean having expended all her torpedoes.

15Dotta, Antonio30 Jul 19412025Cagliari6 Aug 19410650Cagliari432Patrolled off Cape Bougaroni on 6° E meridian. At 1335 hours on 3rd August, Diaspro was informed of a convoy of eight ships in 37°20'N, 10°45'E, on course 270°, 10 knots and moved westward with the intention to carry out a night attack. Sighted only French ships.

Dotta, Antonio15 Aug 19410815Cagliari15 Aug 19411320CagliariExercises, escorted by the minesweeper Balear.

Dotta, Antonio22 Aug 19410858Cagliari22 Aug 19411335Cagliari22,5Exercises.

Dotta, Antonio23 Aug 19411320Cagliari23 Aug 19411816Cagliari27Exercises.

16Dotta, Antonio24 Aug 19412200Cagliari27 Aug 19411410Cagliari307Patrolled west of La Galite within 10 miles from 37°30'N, 07°40'E.
  25 Aug 1941091037° 48'N, 8° 00'EAt 0010 hours, a submarine believed to be Aradam, was sighted. As a precaution, Diaspro proceeded submerged to her patrol area, which was 25 miles away at the time and again sighted the submarine at 1013 hours.

17Dotta, Antonio12 Sep 19411355Cagliari15 Sep 19411050Cagliari359Patrolled east of La Galite between 37°32'N and North African coast, 08°56'E and 09°20'E.
  12 Sep 19411855
1852 (e)
38° 42'N, 9° 30'EAt 1855 hours, Diaspro was mistaken for an enemy submarine and attacked by Cant Z.506 no. 3 of 188^ Squadriglia based at Elmas. The aircraft dropped two bombs set to explode at a depth of 15 meters. The submarine was shaken, but escaped by diving to 70 meters. The aircraft observer G.M. Paolo Tavolato was reprimanded.

18Dotta, Antonio16 Sep 19412355Cagliari17 Sep 19412145Cagliari184Sailed for patrol off SE of Minorca to form a patrol line with Serpente but then recalled. Uneventful.
  17 Sep 19411240At 1240 hours, the submarine Serpente was sighted at a distance 8,000 metres on opposite course. Diaspro had received the recall order but Serpente had not yet.

19Dotta, Antonio25 Sep 19411835Cagliari2 Oct 19411100Cagliari814Sailed with Axum, Aradam and Serpente for patrol between 39°10'N and 39°50'N, and between 06°40'E and 07°00'E on a patrol line with them. On 27th September, was moved 100 miles south (in 38°25'N then moved to 37°30'N, 07°00'E on 28th September) then off Cape Bougaroni.
  29 Sep 19410617
0612 (e)
37° 32'N, 6° 45'EAt 0617 hours, in dense rain showers, a destroyer was suddenly sighted at a distance of 250 metres. Almost at the same another large shadow appeared at 2,500-3,000 metres. Diaspro fired her two stern tubes and crash-dived. After 3 minutes a loud explosion was heard as the submarine was at a depth of 30 metres.

This was the destroyer HMS Gurkha, on the port side of the screen of HMS Ark Royal, HMS Prince of Wales and HMS Rodney, covering the HALBERD convoy. The destroyer sighted the torpedo wakes and managed to avoid them. At 0622 hours, she heard two explosions, which were probably the torpedoes reaching the end of their run. The Dutch destroyer HrMs Isaac Sweers joined the hunt, but did not drop any depth-charges. HMS Gurkha got a contact at 0810 hours, in 37°26' N, 07°14' E and ,dropped fourteen depth-charges. With the fleet proceeding at 17 knots on an easterly course, it could not have been the same submarine.
  1 Oct 19410814
(0) Near La Galite.
At 0814 hours, a submarine believed to be Aradam was sighted.
  2 Oct 19410700
(0) Near Cagliari.
At 0700 hours, the submarine Serpente was sighted.

20Dotta, Antonio16 Oct 19412355Cagliari21 Oct 19411225Cagliari540Sailed with Aradam, Serpente, Turchese and Alagi for patrol north of Cape de Fer between 37°30'N and 37°40'N, and between 06°40'E and 07°20'E on a patrol line with them (the four submarines were spread from 37°10'N to 37°50'N, each occupying a zone 10 miles deep).
  17 Oct 19410715-101038° 27'N, 8° 28'EAt 0700 hours, the submarine Serpente was sighted at 8,000 metres and remained in sight until 1010 hours.
  20 Oct 19411900
1650 (e)
38° 05'N, 8° 00'EAt 1900 hours, three vessels were sighted at over 10,000 metres. They were recognised as destroyers, two of the FEARLESS class and one of the JERVIS class. These were probably the light cruisers HMS Aurora and HMS Penelope and the destroyers HMS Lance and HMS Lively (Force K) proceeding to Malta. Diaspro could not close to carry out an attack.

21Dotta, Antonio24 Oct 19412305Cagliari3 Nov 19411415Cagliari972Sailed for patrol with Alagi, between 37°15'N and 37°30'N and, and between 05°20'E and 06°00'E. Uneventful. Heard only H.E.

Dotta, Antonio12 Nov 19411845Cagliari14 Nov 19410920Messina345,5Passage Cagliari-Messina, surfaced at 9 knots.

Dotta, Antonio17 Nov 19411035Messina20 Nov 19411435Pola680Passage Messina-Pola, surfaced at 9 knots. The submarine was informed that she might encounter a convoy escorted by the torpedo boat Libra at 0100 hours on the 18th.

Dotta, Antonio22 Nov 19410830Pola22 Nov 19411510Fiume62Passage Pola-Fiume.

Dotta, Antonio26 Feb 19420910Fiume26 Feb 19421800Fiume43Trials escorted by the auxiliary Abbazia.

Dotta, Antonio2 Apr 19420950Fiume2 Apr 19421830Fiume59Trials, escorted by the torpedo boat T.7.

Dotta, Antonio9 Apr 19421610Fiume9 Apr 19421625Sussa (Fiume)2Passage Fiume-Sussa.

Dotta, Antonio11 Apr 19420850Sussa (Fiume)11 Apr 19421900Sussa (Fiume)19Exercises, escorted by the torpedo boat Insidioso and the auxiliary Jadera.

Dotta, Antonio15 Apr 19421240Sussa (Fiume)16 Apr 19420030Sussa (Fiume)63Exercises, escorted by the torpedo boat Insidioso and the auxiliary Trau.

Dotta, Antonio17 Apr 19421240Sussa (Fiume)17 Apr 19421730Sussa (Fiume)38Exercises with the submarine Bandiera, escorted by the auxiliary Trau.

Dotta, Antonio20 Apr 19422035Sussa (Fiume)21 Apr 19420115Sussa (Fiume)36Exercises, escorted by the auxiliary Trau.

Dotta, Antonio22 Apr 19421225Sussa (Fiume)22 Apr 19422015Sussa (Fiume)28Exercises, escorted by the torpedo boat T.3 and the auxiliary Trau.

Dotta, Antonio24 Apr 19421400Sussa (Fiume)25 Apr 19420035Sussa (Fiume)68Exercises.

Dotta, Antonio25 Apr 19420830Sussa (Fiume)25 Apr 19421110Sussa (Fiume)9Exercises.

Dotta, Antonio27 Apr 19420925Sussa (Fiume)27 Apr 19421240Sussa (Fiume)9Exercises.

Dotta, Antonio27 Apr 19422015Sussa (Fiume)28 Apr 19420040Sussa (Fiume)31Exercises with the submarines Bandiera and Giada, escorted by the torpedo Audace.

Dotta, Antonio1 May 19420650Sussa (Fiume)1 May 19421235Sussa (Fiume)32Exercises, escorted by the torpedo boat Audace.

Dotta, Antonio1 May 19422020Sussa (Fiume)2 May 19420110Sussa (Fiume)28Exercises, escorted by the torpedo boat Audace.

Dotta, Antonio4 May 19421230Sussa (Fiume)5 May 19420200Sussa (Fiume)64Exercises with the submarine Manara, escorted by the torpedo boat Audace.

Dotta, Antonio6 May 19420920Sussa (Fiume)6 May 19421225Sussa (Fiume)18Exercises.

Dotta, Antonio6 May 19421420Sussa (Fiume)6 May 19421710Sussa (Fiume)17Exercises.

Dotta, Antonio8 May 19421410Sussa (Fiume)8 May 19421920Sussa (Fiume)17Exercises with the submarine Manara, escorted by the auxiliary Jadera.

Dotta, Antonio12 May 19421310Sussa (Fiume)13 May 19420200Sussa (Fiume)60Exercises with the submarines Giada and Bandiera, escorted by the torpedo boat T.3.

Dotta, Antonio14 May 19421100Sussa (Fiume)15 May 19420140Sussa (Fiume)68Exercises with the submarine Bandiera, escorted by the torpedo boat Insidioso.

Dotta, Antonio16 May 19420650Sussa (Fiume)16 May 19421350Sussa (Fiume)24,5Exercises.

Dotta, Antonio27 Jun 19420510Fiume27 Jun 19421800Venice131Passage Fiume-Venice to test the "Silenta" apparatus.

Dotta, Antonio30 Jun 19421020Venice30 Jun 19421340Venice13Exercises.

Dotta, Antonio1 Jul 19420950Venice1 Jul 19421430Venice11Exercises.

Dotta, Antonio4 Jul 19420520Venice4 Jul 19421900Fiume133Passage Venice-Fiume.

Dotta, Antonio5 Jul 19420920Fiume5 Jul 19421220Fiume11Exercises.

Dotta, Antonio15 Jul 19421030Fiume15 Jul 19421110Sussa (Fiume)1Passage Fiume-Sussa.

Dotta, Antonio16 Jul 19421426Sussa (Fiume)17 Jul 19420245Sussa (Fiume)46Exercises.

Dotta, Antonio20 Jul 19421500Sussa (Fiume)21 Jul 19420125Sussa (Fiume)34Exercises.

Dotta, Antonio22 Jul 19421305Sussa (Fiume)22 Jul 19422335Sussa (Fiume)31Exercises.

Dotta, Antonio24 Jul 19421300Sussa (Fiume)25 Jul 19420115Sussa (Fiume)48Exercises.

Dotta, Antonio28 Jul 19421235Sussa (Fiume)28 Jul 19421755Sussa (Fiume)26Exercises.

Dotta, Antonio30 Jul 19420735Sussa (Fiume)30 Jul 19421650Sussa (Fiume)72Exercises.

Dotta, Antonio31 Jul 19420300Sussa (Fiume)31 Jul 19421900Sussa (Fiume)46Exercises.

Dotta, Antonio3 Aug 19421315Sussa (Fiume)4 Aug 19420115Sussa (Fiume)50Exercises.

Dotta, Antonio5 Aug 19421235Sussa (Fiume)6 Aug 19420040Sussa (Fiume)52Exercises.

Dotta, Antonio7 Aug 19421230Sussa (Fiume)8 Aug 19420040Sussa (Fiume)57Exercises.

Dotta, Antonio11 Aug 19420935Sussa (Fiume)11 Aug 19421335Sussa (Fiume)14Exercises.

Dotta, Antonio13 Aug 19421425Sussa (Fiume)14 Aug 19420005Sussa (Fiume)56Exercises.

Dotta, Antonio17 Aug 19421430Sussa (Fiume)18 Aug 19420010Sussa (Fiume)56Exercises.

Dotta, Antonio19 Aug 19420735Sussa (Fiume)19 Aug 19420810Fiume2Passage Sussa-Fiume.

Dotta, Antonio26 Aug 19421330Fiume26 Aug 19421700Fiume13Trials.

Dotta, Antonio27 Aug 19420540Fiume27 Aug 19421845Venice127Passage Fiume-Venice.

Dotta, Antonio29 Aug 19420850Venice29 Aug 19421150Venice10Trials.

Dotta, Antonio2 Sep 19420700Venice2 Sep 19421450Pola78,5Passage Venice-Pola.

Dotta, Antonio5 Sep 19421200Pola5 Sep 19421920Pola43Exercises with the torpedo boat Fortunale in 44°45'N, 13°27'E.

Dotta, Antonio10 Sep 19421400Pola15 Sep 19421010Trapani950Passage Pola-Trapani. She was informed that she would probably cross the path of a German submarine (this was U-205) at 1400 hours on the 11th, and the submarine Micca at dawn on the 13th.

Dotta, Antonio24 Oct 19420730Trapani24 Oct 19421235Trapani31Exercises.

22Dotta, Antonio7 Nov 19420145Trapani14 Nov 19421830Trapani1820,5Patrolled in 37°25'N, 10°15'E to attack an enemy convoy. On 8 November, moved to area between 37°00'N and 37°20'N, and between 06°00'E and 06°20'E.
  8 Nov 1942115835° 25'N, 10° 15'EAt 1158 hours, Diaspro collided with the submarine Alagi as they were proceeding submerge to their patrol areas. Diaspro was at a depth of 12 metres at the time and suffered only minor damages but Alagi had to return to base for repairs.
  12 Nov 1942050536° 46'N, 5° 06'EAt 0456 hours, a large vessel was sighted at a distance of 1,200 metres. She was estimated doing 14 knots.

At 0505 hours, Diaspro fired all four bow tubes (533mm, G7e type) at a range of 800 metres, adjusted for an enemy's speed of 10 knots as the initial speed appeared to have been overestimated. However, the torpedoes had just left the tubes when the vessel altered course to port and they missed.

This was probably the Dutch liner Marnix Van St. Aldegonde (19,355 GRT, built 1930) who anchored off Cape Bouak at 0800 hours coming from Cape Aokas [36°38'45" N, 05°13'54" E] where she had taken refuge the previous day.

At 0510 hours, the submarine had reverted and fired a single stern torpedo from a range of 1,500 metres. At 0513 hours, a double explosion was heard.

No vessels reported being torpedoed at this time.

Dotta, Antonio16 Nov 19421905Trapani17 Nov 19422145Naples237Passage Trapani-Naples.

Dotta, Antonio20 Nov 19420800Naples20 Nov 19421150Naples10Exercises.

Dotta, Antonio25 Nov 19421500Naples26 Nov 19422017La Maddalena231Passage Naples-La Maddalena.

23Donato, Alberto2 Dec 19420316La Maddalena4 Dec 19420006La Maddalena278,5Defensive patrol near La Maddalena, between 41°40'N and 41°55'N, and between 08°20'E and Corsican coast. Uneventful.

Donato, Alberto6 Dec 19421745La Maddalena7 Dec 19421530Cagliari197,6Passage La Maddalena-Cagliari.

24Donato, Alberto12 Dec 19422345Cagliari24 Dec 19420925Cagliari1032,5Patrolled in Western Mediterranean between 38°00'N and 38°20'N, and between 08°20'E and 08°40'E.
  13 Dec 19420725At 0725 hours, three German aircraft were seen and exchanged recognition signals with Diaspro.
  13 Dec 19420930At 0930 hours, an Italian aircraft was seen and exchanged recognition signals with Diaspro.
  21 Dec 1942005538° 05'N, 8° 30'EAt 0055 hours, a vessel initially believed to be a submarine was sighted but may have been an A/S vessel. Diaspro submerged and heard explosions coming from the direction of the vessel.
  22 Dec 19422240-224538° 12'N, 8° 29'EAt 2245 hours, a submarine was sighted on a northerly course. This was perhaps HMS P 247 (later named HMS Saracen). Diaspro lost contact in a rain squall.
  23 Dec 1942025538° 12'N, 8° 27'EAt 0255 hours, a submarine was sighted on a northerly course at a distance of 3,000 metres. This was perhaps HMS P 247 again. Diaspro lost contact.

Donato, Alberto1 Jan 19431457Cagliari2 Jan 19432110Naples271Passage Cagliari-Naples.

Donato, Alberto20 Feb 19430836Naples20 Feb 19431401Naples17Exercises and trials.

Donato, Alberto23 Feb 19431340Naples23 Feb 19431830Naples22,5Exercises and trials.

Donato, Alberto24 Feb 19431343Naples24 Feb 19432030Naples25Exercises and trials.

Donato, Alberto27 Feb 19431009Naples27 Feb 19431633Naples29Exercises and trials.

Donato, Alberto20 Mar 19430820Naples20 Mar 19431747Naples21Gyrocompass tests and exercises.

Donato, Alberto21 Mar 19431535Naples21 Mar 19431947Naples7Exercises.

Donato, Alberto23 Mar 19431018Naples23 Mar 19431331Naples19Exercises.

Donato, Alberto24 Mar 19431212Naples24 Mar 19431355Pozzuoli12,5Exercises.

Donato, Alberto25 Mar 19430855Pozzuoli25 Mar 19431551Pozzuoli28Exercises.

Donato, Alberto26 Mar 19430824Pozzuoli26 Mar 19431607Pozzuoli37Exercises.

Donato, Alberto3 Apr 19431400Pozzuoli3 Apr 19431555Naples12,5Passage Pozzuoli-Naples.

Donato, Alberto4 Apr 19430045Naples5 Apr 19430645La Maddalena250,2Passage Naples-La Maddalena.

Donato, Alberto7 Apr 19430853La Maddalena7 Apr 19431747Ajaccio68,1Passage La Maddalena-Ajaccio.

25Donato, Alberto2 May 19432310Ajaccio17 May 19431215La Maddalena1076,2Patrolled in Western Mediterranean, between 39°00'N and 39°40'N, and between 05°00'E and 05°40'E.
  12 May 1943225138° 56'N, 5° 22'EAt 2251 hours, an aircraft was seen at 1,000 metres and the submarine dived. When it reached a depth of 50 meters, a leak was noticed, through the stern torpedo tube no. 6. Diaspro surfaced and at 0545 hours on the 13th, a rating donned a diving apparatus and managed to remove an obstruction from the tube door stopping the leak.
  17 May 19430630
(0) 058° - Porto Torres - 4.7 miles.
At 0630 hours, Diaspro came under fire from an Italian coastal battery when she was mistaken for an enemy submarine. Fortunately, the nearest round fell some 800 meters short and, after making recognition signals and displaying the Italian flag, the battery checked fire.

Donato, Alberto27 May 19431100La Maddalena27 May 19431202Porto Palma3,5Passage La Maddalena-Porto Palma.

Donato, Alberto28 May 19430925Porto Palma28 May 19431030Mezzo Schifo4Passage Porto Palma-Mezzo Schifo.

Donato, Alberto6 Jun 19430920Mezzo Schifo6 Jun 19431010Villamarina2Passage Mezzo Schifo-Villamarina.

Donato, Alberto10 Jun 19430455Cala Villamarina10 Jun 19430820Bonifacio21,5Passage Cala Villamarina-Bonifacio.

Donato, Alberto18 Jun 19431342Bonifacio18 Jun 19431730La Maddalena23,5Passage Bonifacio-La Maddalena.

Donato, Alberto22 Jun 19430855La Maddalena22 Jun 19431000G. Salina5Passage Bonifacio-G. Salina.

Donato, Alberto24 Jun 19431030G. Salina24 Jun 19431104Porto Palma2,5Passage G. Salina-Porto Palma.

Donato, Alberto26 Jun 19430507Porto Palma26 Jun 19430826Bonifacio23,5Passage Porto Palma-Bonifacio.

Donato, Alberto28 Jun 19430755Bonifacio28 Jun 19431255Bonifacio20Exercises.

Donato, Alberto1 Jul 19430830Bonifacio1 Jul 19431330BonifacioExercises.

Donato, Alberto3 Jul 19430500Bonifacio3 Jul 19430732La Maddalena23,5Passage Bonifacio-La Maddalena.

Donato, Alberto6 Jul 19430500Mezzoschifo6 Jul 19431220Ajaccio65,8Passage Mezzoschifo-Ajaccio.

26Donato, Alberto10 Jul 19430400Ajaccio16 Jul 19430630Naples753Sailed with Platino. Patrolled in Western Mediterranean in zone 99 [between 37°20'N and North African coast, and between 07°20'E and 07°40'E], off Cap de Fer (Algeria).
  11 Jul 19432141
(0) Near Sardinia.
At 2141 hours, a submarine was sighted on a southerly course at a distance of 5,000 metres. Shortly after, another submarine was sighted at a distance of 3,000 metres steering WNW. Diaspro took avoiding action.
  13 Jul 1943011337° 05'N, 7° 40'EAt 0000 hours, two shadows were sighted. The submarine closed to 5,000 metres and identified them as two 10,000-ton steamers. Shortly after, a destroyer was sighted in between them. At 0007 hours, the destroyer, closing on Diaspro, was now at 1,000 metres and T.V. Donato decided to dive to 60 metres.

At 0102 hours, the submarine surfaced and immediately sighted a large steamer escorted by two corvettes at a distance of 3,000 metres.

At 0113 hours, four torpedoes were fired from the bow tubes, at a distance of 2,500 metres, at the steamer estimated to be of 15,000 tons. Her speed was intially estimated to 15 knots, but later corrected to 8 knots. It was then realised that the vessel was perhaps going at a slower speed causing the torpedoes to miss. Diaspro now reverted course.

At 0120 hours, the two stern torpedoes were fired at a range of 2,500 metres. Two hits were heard after 148 seconds but no such success is confirmed in British documents.

The target has not yet been identified.

27Donato, Alberto23 Jul 19432205Naples3 Aug 19430738Naples887,7Patrolled off Pantelleria and east coast of Sicily for operation ZETA.
  25 Jul 19430300
(0) Near Point M3 (near Cape Vaticano).
At 0300 hours, a hospital ship was sighted on a southerly course.
  25 Jul 19430310
(0) Near Point M3 (near Cape Vaticano).
At 0310 hours, two Italian steamers and a corvette were encountered on an opposite course. This was the convoy consisting of Viminale, Magliulo and Petsamo escorted by the torpedo boat Pallade, the corvette Gabbiano and the tug Forte and Tenax sailing from Messina for Naples. Pallade fired four star shells before recognising the submarine.
  26 Jul 1943022037° 38'N, 16° 38'EAt 0220 hours, an aircraft was seen and the submarine dived.
  26 Jul 19432133At 2133 hours, a MTB was sighted and Diaspro dived to 50 metres.
  27 Jul 19430243At 0243 hours, a MTB was sighted and Diaspro dived.
  27 Jul 1943040536° 30'N, 16° 09'EAt 0405 hours, an aircraft was seen and the submarine dived.
  27 Jul 19430440At 0440 hours, several aircraft were seen and the submarine dived.
  27 Jul 1943230836° 20'N, 15° 02'EAt 2308 hours, flares apparently dropped by an aircraft were seen and the submarine dived.
  28 Jul 19430232At 0232 hours, a MTB was seen and the submarine dived.
  28 Jul 1943171336° 22'N, 14° 40'EAt 1713 hours, an aircraft was seen when Diaspro was at periscope depth. She went deep.
  28 Jul 19432345At 2345 hours, a MTB was seen and the submarine dived.
  29 Jul 19430120At 0120 hours, a MTB was seen and the submarine dived to 50 metres.
  29 Jul 19432210At 2210 hours, a hospital ship was sighted and the submarine crash-dived, perhaps to avoid a collision.
  2 Aug 1943221539° 07'N, 11° 56'EAt 2215 hours, flares, apparently dropped by an aircraft, were seen and the submarine dived.

Donato, Alberto11 Aug 19430800Naples11 Aug 19431257Naples7Exercises.

28Donato, Alberto15 Aug 19430830Naples22 Aug 19430725Naples335,6Patrolled north of the Strait of Messina between parallel of Stromboli and coast.
  18 Aug 1943005238° 41'N, 15° 20'EAt 0048 hours, two enemy destroyers were sighted, steering 149° at a distance of 8,000 metres.

At 0052 hours, Diaspro fired two stern torpedoes (533mm, S.I. type) at a distance of 5,000 metres. They missed.
  19 Aug 1943232338° 42'N, 15° 20'EAt 2319 hours, two destroyers were sighted steering 099°. Diaspro fired four torpedoes (533mm, G7e type) from her bow tubes at a range of 3,500 metres. Two were claimed to have hit. T.V. Donato believed he had sunk one and damaged the other.

At 0145 hours, an immobilised destroyer was sighted but the submarine had expended all her torpedoes and could not finish her off.

Unfortunately, the results were not confirmed. This was the last attack by an Italian submarine in the Mediterranean Theatre.

Donato, Alberto28 Aug 19430920Naples28 Aug 19431604Naples37,8Exercises.

Donato, Alberto29 Aug 19431350Naples29 Aug 19431555Naples10,3Exercises.

29Donato, Alberto3 Sep 19430131Naples5 Sep 19430852Naples231,1Defensive patrol in Gulf of Policastro.
  4 Sep 19430820At 0820 hours, a buoy similar in shape to a mine was sunk by machine gun fire.

Donato, Alberto7 Sep 19431448La Maddalena12 Sep 19431239Cagliari474,3Sailed for patrol in Gulf of Salerno, when the Armistice ordered her to Bone (Algeria) but because of defects to her port side diesel, she had to go to Cagliari where she surrendered. She required repairs to be completed by the end of October but this was delayed until mid-December because of lack of spare parts.
  7 Sep 19432130at 2130 hours, a hospital ship was seen at a distance of 3,000 metres.

Botta, Emilio9 Dec 19430945Cagliari9 Dec 19431233Cagliari7,5Trials after repairs.

Botta, Emilio18 Dec 19431320Cagliari20 Dec 19431020Palermo224Passage Cagliari-Palermo with steamer Lucera and the torpedo boat Carini.

Botta, Emilio21 Dec 19432312Palermo23 Dec 19431050Augusta195Passage Palermo-Augusta with the British steamers Empire Fay, Lucera and Portsea and the American Conasauga and escorted by the destroyer Carini and the torpedo boat Clio.

Botta, Emilio21 Jan 19440720Augusta21 Jan 19441353Augusta33Exercises.

Botta, Emilio16 Feb 19440905Augusta18 Feb 19440930Brindisi291Passage Augusta-Brindisi with a convoy escorted by destroyer Granatiere, the torpedo boats Libra and Monzambano and the corvettes Sfinge and Fenice.

Botta, Emilio16 Jul 19440805Brindisi16 Jul 19441626Brindisi35Trials.

Botta, Emilio19 Jul 19440800Brindisi19 Jul 19441740Brindisi54,8Trials.

Botta, Emilio22 Jul 19440820Brindisi22 Jul 19441625Brindisi46,4Exercises.

Botta, Emilio28 Jul 19440830Brindisi28 Jul 19441610Brindisi40,8Exercises.

Botta, Emilio29 Jul 19440935Brindisi29 Jul 19441653Brindisi?Gyrocompass tests.

Botta, Emilio5 Aug 19440810Brindisi5 Aug 19441515Brindisi28,9Exercises.

Botta, Emilio9 Aug 19440836Brindisi9 Aug 19441601Brindisi23,5Exercises.

30Botta, Emilio17 Aug 19440751Brindisi22 Aug 19440956Brindisi542,9Special operation. Landed a group on Zante and another on Cephalonia.
  19 Aug 19440020-0152
(0) Zante Island.
Between 0020 and 0152 hours, Diaspro landed four agents on the island of Zante (one British officer, one Greek officer and two other ranks).
  20 Aug 19440100-0425
(0) Cephalonia.
Between 0100 and 0425 hours, Diaspro landed agents on the island of Cephalonia.

Botta, Emilio16 Sep 19440800Brindisi16 Sep 19441500Brindisi42Exercises.

Botta, Emilio13 Oct 19440909Brindisi14 Oct 19440932Taranto163Passage Brindisi-Taranto with the submarine Platino and the corvette Minerva.

Botta, Emilio16 Oct 19440838Taranto16 Oct 19441730Taranto24Exercises.

Botta, Emilio18 Oct 19440753Taranto18 Oct 19442330Taranto45,7Exercises.

Botta, Emilio23 Oct 19441420Taranto23 Oct 19442145Taranto32,6Exercises.

Botta, Emilio28 Oct 19440618Taranto28 Oct 19441455Taranto20Exercises.

Botta, Emilio30 Oct 19441135Taranto30 Oct 19442020Taranto34Exercises.

Botta, Emilio3 Nov 19441132Taranto3 Nov 19441542Taranto22,2Exercises.

Botta, Emilio7 Nov 19441555Taranto7 Nov 19442021Taranto23,3Exercises.

Botta, Emilio13 Nov 19441430Taranto14 Nov 19441448Brindisi154,6Passage Taranto-Brindisi with the submarine Alagi and the torpedo boat Sagittario.

Tarabini Castellani, Giovanni20 Dec 19440812Taranto20 Dec 19441640Brindisi36Exercises.

Tarabini Castellani, Giovanni28 Dec 19440810Taranto28 Dec 19441643Brindisi19,4Exercises.

Tarabini Castellani, Giovanni8 Jan 19450847Brindisi9 Jan 19450900Taranto153,1Passage Brindisi-Taranto with the destroyer Artigliere.

Tarabini Castellani, Giovanni15 Jan 19450658Taranto15 Jan 19451730Taranto29Exercises.

Tarabini Castellani, Giovanni17 Jan 19450700Taranto17 Jan 19451658Taranto14,3Exercises.

Tarabini Castellani, Giovanni19 Jan 19450720Taranto19 Jan 19451535Taranto14,2Exercises.

Tarabini Castellani, Giovanni25 Jan 19450640Taranto25 Jan 19451510Taranto22,1Exercises.

Tarabini Castellani, Giovanni27 Jan 19450651Taranto27 Jan 19451515Taranto19,6Exercises.

Tarabini Castellani, Giovanni30 Jan 19450700Taranto30 Jan 19451654Taranto53,4Exercises.

Tarabini Castellani, Giovanni31 Jan 19450745Taranto31 Jan 19451552Taranto14,6Exercises.

Tarabini Castellani, Giovanni5 Feb 19450855Taranto5 Feb 19452215Taranto60,7Exercises.

Tarabini Castellani, Giovanni6 Feb 19450708Taranto6 Feb 19451611Taranto23,2Exercises.

Tarabini Castellani, Giovanni13 Feb 19450639Taranto13 Feb 19451610Taranto6,5Exercises.

Tarabini Castellani, Giovanni23 Feb 19450658Taranto23 Feb 19451548Taranto29,1Exercises.

Tarabini Castellani, Giovanni24 Feb 19450600Taranto24 Feb 19451610Taranto58,4Exercises.

Tarabini Castellani, Giovanni1 Mar 19450637Taranto1 Mar 19451538Taranto22,6Exercises.

Tarabini Castellani, Giovanni13 Mar 19450937Taranto14 Mar 19450205Taranto67Exercises.

Tarabini Castellani, Giovanni14 Mar 19450814Taranto14 Mar 19451600Taranto31Exercises.

Tarabini Castellani, Giovanni15 Mar 19451236Taranto16 Mar 19451058Brindisi150,1Passage Taranto-Brindisi, towing MAS 510 with the torpedo boat Animoso towing the pontoon G.G.S.185.

Tarabini Castellani, Giovanni22 Mar 19450900Brindisi22 Mar 19451620Brindisi28Exercises.

Tarabini Castellani, Giovanni24 Mar 19450900Brindisi24 Mar 19451645Brindisi28,2Exercises.

Tarabini Castellani, Giovanni30 Mar 19450900Brindisi30 Mar 19451610Brindisi23,5Exercises.

Tarabini Castellani, Giovanni4 Apr 19450820Brindisi4 Apr 19451726Brindisi32Exercises.

Tarabini Castellani, Giovanni7 Apr 19450812Brindisi7 Apr 19451450Brindisi14,7Exercises.

Tarabini Castellani, Giovanni10 Apr 19451000Brindisi12 Apr 19450859Malta401Passage Brindisi-Malta with the torpedo boat Animoso. Used for A/S school until August 1945.

Tarabini Castellani, Giovanni13 Apr 19451000Sliema (Malta)13 Apr 19450859Sliema (Malta)56Exercises.

Tarabini Castellani, Giovanni14 Apr 19450625Sliema (Malta)14 Apr 19451950Sliema (Malta)56Exercises.

Tarabini Castellani, Giovanni16 Apr 19450635Sliema (Malta)16 Apr 19452017Sliema (Malta)69Exercises.

Tarabini Castellani, Giovanni20 Apr 19451005Sliema (Malta)20 Apr 19452058Sliema (Malta)53Exercises.

Tarabini Castellani, Giovanni21 Apr 19450640Sliema (Malta)21 Apr 19451455Sliema (Malta)43Exercises.

Tarabini Castellani, Giovanni23 Apr 19451030Sliema (Malta)23 Apr 19451345Sliema (Malta)48,5Exercises.

Tarabini Castellani, Giovanni24 Apr 19451055Sliema (Malta)24 Apr 19452005Sliema (Malta)47Exercises.

Tarabini Castellani, Giovanni25 Apr 19450658Sliema (Malta)25 Apr 19451524Sliema (Malta)43Exercises.

Tarabini Castellani, Giovanni27 Apr 19450640Sliema (Malta)27 Apr 19451635Sliema (Malta)47Exercises.

Tarabini Castellani, Giovanni1 May 19450620Sliema (Malta)1 May 19451535Sliema (Malta)53Exercises.

Tarabini Castellani, Giovanni3 May 19450645Sliema (Malta)3 May 19451515Sliema (Malta)42,5Exercises.

Tarabini Castellani, Giovanni5 May 19450658Sliema (Malta)5 May 19451644Sliema (Malta)57Exercises.

Tarabini Castellani, Giovanni7 May 19451030Sliema (Malta)7 May 19452012Sliema (Malta)50Exercises.

Tarabini Castellani, Giovanni13 May 19450655Sliema (Malta)13 May 19451942Sliema (Malta)52Exercises.

Tarabini Castellani, Giovanni16 May 19450646Sliema (Malta)16 May 19451535Sliema (Malta)44Exercises.

Tarabini Castellani, Giovanni18 May 19450500Sliema (Malta)18 May 19451340Sliema (Malta)56Exercises.

Tarabini Castellani, Giovanni21 May 19450847Sliema (Malta)21 May 19451600Sliema (Malta)43Exercises.

Tarabini Castellani, Giovanni27 May 19450806Malta27 May 19452113Augusta110Passage Malta-Augusta.

Tarabini Castellani, Giovanni28 May 19452336Augusta29 May 19450949AugustaPassage Augusta-Taranto, but turned back because of defects.

Tarabini Castellani, Giovanni28 May 19452336Augusta29 May 19450949Augusta80Passage Augusta-Taranto, but turned back because of defects.

Tarabini Castellani, Giovanni29 May 19452330Augusta31 May 19450836Taranto251Passage Augusta-Taranto.

Tarabini Castellani, Giovanni15 Aug 19450712Taranto15 Aug 19451348Taranto21Exercises.

Tarabini Castellani, Giovanni17 Aug 19451603Taranto17 Aug 19452101Taranto33,5Exercises.

Tarabini Castellani, Giovanni20 Aug 19451559Taranto20 Aug 19452224Taranto33,6Exercises.

Tarabini Castellani, Giovanni22 Aug 19451000Taranto22 Aug 19451822Taranto50,4Exercises.

Tarabini Castellani, Giovanni24 Aug 19450625Taranto24 Aug 19451805Taranto55Exercises.

Tarabini Castellani, Giovanni25 Aug 19450610Taranto25 Aug 19451335Taranto23,2Exercises.

Tarabini Castellani, Giovanni28 Aug 19450613Taranto28 Aug 19451613Taranto42Exercises.

Tarabini Castellani, Giovanni30 Aug 19450606Taranto30 Aug 19451621Taranto27,9Exercises.

249 entries. 224 total patrol entries (30 marked as war patrols) and 42 events.

Events

GH 09.03.2021: This table kept here until we make fix the possible missing events in table above

CommanderDateTimePositionDescription
Marino Salvatori1 Sep 19400610
0720 (e)
(e) 38.20 N, 07.40 E
At 0610 hours, a Sunderland was sighted at a short distance coming head on. It passed Diaspro on the starboard side and T.V. Marino Salvatori ordered the submarine to dive. As she did so, the aircraft made a stern attack, strafing her. The submarine reached a depth of 40-50 metres and proceed westward.

At 0740 hours, five bombs were heard, one of them loudly ahead, the others more distant on both sides. Corallo went down to 70-80 metres. Hydrophone noises were heard and the submarine moved away from them. At 0854 hours, an explosion was heard. At 1035 hours, five explosions were heard astern. At 1220 hours, three explosions was heard to starboard. At 1707 hours, a bomb was heard ahead and finally at 1725 hours five bombs were heard astern.

The attacking aircraft was a Swordfish from the aircraft carrier HMS Ark Royal.
Marino Salvatori17 Nov 19401030(o) North of Cape Bougaroni.At 1030 hours, a British destroyer of the "H" class was sighted at a distance of 7,000 metres, steering 080°, 12 knots. Diaspro could not close the range for an attack.
Antonio Dotta22 Jul 19412307
2310 (e)
38.10 N, 05.30 E
(e) 38.02 N, 05.39 E
At 1005 hours, as Cape Bougaroni was in sight, information was received that, at 0850 hours, an aircraft had spotted a large naval force in 38°26' N, 03°25' E.

At 1130 hours, a signal from MARICOSOM revealed that a force of one battleship, one aircraft carrier and four destroyers had been sighted at 0920 hours in 38°26' N, 03°35' E, steering 090° at 18 knots. T.V. Antonio Dotta estimated that this force could be 45 miles north of his position, at 1630 hours. He immediately altered course, expecting to reach the interception course at 1600 hours.

At 1440 hours, as Diaspro was proceeding northward, an order from MARICOSOM gave her freedom of action to move outside her patrol area to intercept the enemy.

At 1920 hours, a new signal from MARICOSOM reported the enemy's position at 1545 hours as 75 miles north of Cape Bougaroni, steering 090° at 20 knots. It was now described as one battleship, one aircraft carrier and seven destroyers. However, this position was only 7 miles from Diaspro at 1545 hours and, since no hydrophone noises had been picked up, Dotta estimated that the position provided by MARICOSOM was erroneous. At 1950 hours, bomb explosions could be heard to the west.

At 2015 hours, Diaspro was informed by MARICOSOM that an enemy naval force had been reported at 1505 hours, 75 miles north of Cape Sigli, consisting of a battleship, an aircraft carrier, four cruisers and five destroyers. It was not clear if this was the same force or a different one. At 2200 hours, the submarine submerged briefly to listen with the hydrophones and detected numerous noises westward. All forward tubes were readied as Corallo proceeded on the surface.

At 2258 hours, shadows were sighted and, two minutes later, the diesels were stopped and the electric motors switched on for a silent approach.

At 2304 hours, a naval force of eight to ten ships was sighted in the process of reverting course from 090° to 270°. It could now be identified as one or two destroyers leading the formation, followed by four cruisers, other destroyers, a battleship, an aircraft carrier and one or two destroyers bringing up the rear. The speed was estimated at 10 knots and distances varied from 1,000 to 1,300 metres.

At 2307 hours, a full salvo of four torpedoes was fired from the bow tubes aimed at the cruisers. They missed. T.V. Dotta believed that the very visible phosphorescence of the torpedo tracks had enabled the enemy to take avoiding action.

At 2309 hours, Diaspro had reverted course to fire two stern torpedoes aimed at the battleship and aircraft carrier from 700 metres and then crash-dived. Two explosions were heard about a minute after firing leading Dotta to believe that he had scored one or perhaps both the major units.

This was Force H covering the SUBSTANCE convoy, with the battle cruiser HMS Renown, the battleship HMS Nelson, the light cruiser HMS Hermione, the aircraft carrier HMS Ark Royal and screened by destroyers. One of these destroyers, HMAS Nestor, stationed on the starboard wing, reported two torpedoes, which were avoided. Just prior to this, two explosions had been heard which were probably torpedoes from Diaspro's first salvo, either detonating prematurely or hitting the sea bed. The destroyer now obtained an ASDIC contact at 1,700 yards and dropped a pattern of five depth charges set at medium depth, which exploded as the submarine had reached a depth of 40 metres. Another pattern of six depth charges was dropped on a second run and the same number on a third run. Nothing was seen, but there was a strong smell of oil.

In the submarine, about thirty depth charges were heard from 2312 to 0050 hours on 23rd July. Although, the first pattern was close, the remainder were not and the submarine was only slightly damaged. Diaspro had dropped to a depth of 138 metres before stabilising at 116 metres.

At 0330 hours, she made an enemy report and at 0557 hours sighted a squadron of destroyers apparently hunting her. Diaspro dived and proceeded to Cagliari. This is one of the rare instances, when an Italian submarine returned from a patrol in the Mediterranean having expended all her torpedoes.
Antonio Dotta25 Aug 1941091037.48 N, 08.00 E
At 0010 hours, a submarine believed to be Aradam, was sighted. As a precaution, Diaspro proceeded submerged to her patrol area, which was 25 miles away at the time and again sighted the submarine at 1013 hours.
Antonio Dotta12 Sep 19411855
1852 (e)
38.42 N, 09.30 E
At 1855 hours, Diaspro was mistaken for an enemy submarine and attacked by Cant Z.506 no. 3 of 188^ Squadriglia based at Elmas. The aircraft dropped two bombs set to explode at a depth of 15 meters. The submarine was shaken, but escaped by diving to 70 meters. The aircraft observer G.M. Paolo Tavolato was reprimanded.
Antonio Dotta17 Sep 19411240At 1240 hours, the submarine Serpente was sighted at a distance 8,000 metres on opposite course. Diaspro had received the recall order but Serpente had not yet.
Antonio Dotta29 Sep 19410617
0612 (e)
37.32 N, 06.45 E
(e) 37.30 N, 06.25 E
At 0617 hours, in dense rain showers, a destroyer was suddenly sighted at a distance of 250 metres. Almost at the same another large shadow appeared at 2,500-3,000 metres. Diaspro fired her two stern tubes and crash-dived. After 3 minutes a loud explosion was heard as the submarine was at a depth of 30 metres.

This was the destroyer HMS Gurkha, on the port side of the screen of HMS Ark Royal, HMS Prince of Wales and HMS Rodney, covering the HALBERD convoy. The destroyer sighted the torpedo wakes and managed to avoid them. At 0622 hours, she heard two explosions, which were probably the torpedoes reaching the end of their run. The Dutch destroyer HrMs Isaac Sweers joined the hunt, but did not drop any depth-charges. HMS Gurkha got a contact at 0810 hours, in 37°26' N, 07°14' E and ,dropped fourteen depth-charges. With the fleet proceeding at 17 knots on an easterly course, it could not have been the same submarine.
Antonio Dotta1 Oct 19410814(o) Near La Galite.At 0814 hours, a submarine believed to be Aradam was sighted.
Antonio Dotta2 Oct 19410700(o) Near Cagliari.At 0700 hours, the submarine Serpente was sighted.
Antonio Dotta17 Oct 19410715-101038.27 N, 08.28 E
At 0700 hours, the submarine Serpente was sighted at 8,000 metres and remained in sight until 1010 hours.
Antonio Dotta20 Oct 19411900
1650 (e)
38.05 N, 08.00 E
At 1900 hours, three vessels were sighted at over 10,000 metres. They were recognised as destroyers, two of the FEARLESS class and one of the JERVIS class. These were probably the light cruisers HMS Aurora and HMS Penelope and the destroyers HMS Lance and HMS Lively (Force K) proceeding to Malta. Diaspro could not close to carry out an attack.
Antonio Dotta8 Nov 1942115835.25 N, 10.15 E
At 1158 hours, Diaspro collided with the submarine Alagi as they were proceeding submerge to their patrol areas. Diaspro was at a depth of 12 metres at the time and suffered only minor damages but Alagi had to return to base for repairs.
Antonio Dotta12 Nov 1942050536.46 N, 05.06 E
At 0456 hours, a large vessel was sighted at a distance of 1,200 metres. She was estimated doing 14 knots.

At 0505 hours, Diaspro fired all four bow tubes (533mm, G7e type) at a range of 800 metres, adjusted for an enemy's speed of 10 knots as the initial speed appeared to have been overestimated. However, the torpedoes had just left the tubes when the vessel altered course to port and they missed.

This was probably the Dutch liner Marnix Van St. Aldegonde (19,355 GRT, built 1930) who anchored off Cape Bouak at 0800 hours coming from Cape Aokas [36°38'45" N, 05°13'54" E] where she had taken refuge the previous day.

At 0510 hours, the submarine had reverted and fired a single stern torpedo from a range of 1,500 metres. At 0513 hours, a double explosion was heard.

No vessels reported being torpedoed at this time.
Alberto Donato13 Dec 19420725At 0725 hours, three German aircraft were seen and exchanged recognition signals with Diaspro.
Alberto Donato13 Dec 19420930At 0930 hours, an Italian aircraft was seen and exchanged recognition signals with Diaspro.
Alberto Donato21 Dec 1942005538.05 N, 08.30 E
At 0055 hours, a vessel initially believed to be a submarine was sighted but may have been an A/S vessel. Diaspro submerged and heard explosions coming from the direction of the vessel.
Alberto Donato22 Dec 19422240-224538.12 N, 08.29 E
At 2245 hours, a submarine was sighted on a northerly course. This was perhaps HMS P 247 (later named HMS Saracen). Diaspro lost contact in a rain squall.
Alberto Donato23 Dec 1942025538.12 N, 08.27 E
At 0255 hours, a submarine was sighted on a northerly course at a distance of 3,000 metres. This was perhaps HMS P 247 again. Diaspro lost contact.
Alberto Donato12 May 1943225138.56.5 N, 05.22.4 E
At 2251 hours, an aircraft was seen at 1,000 metres and the submarine dived. When it reached a depth of 50 meters, a leak was noticed, through the stern torpedo tube no. 6. Diaspro surfaced and at 0545 hours on the 13th, a rating donned a diving apparatus and managed to remove an obstruction from the tube door stopping the leak.
Alberto Donato17 May 19430630(o) 058° - Porto Torres - 4.7 miles.At 0630 hours, Diaspro came under fire from an Italian coastal battery when she was mistaken for an enemy submarine. Fortunately, the nearest round fell some 800 meters short and, after making recognition signals and displaying the Italian flag, the battery checked fire.
Alberto Donato11 Jul 19432141(o) Near Sardinia.At 2141 hours, a submarine was sighted on a southerly course at a distance of 5,000 metres. Shortly after, another submarine was sighted at a distance of 3,000 metres steering WNW. Diaspro took avoiding action.
Alberto Donato13 Jul 1943011337.05 N, 07.40 E
At 0000 hours, two shadows were sighted. The submarine closed to 5,000 metres and identified them as two 10,000-ton steamers. Shortly after, a destroyer was sighted in between them. At 0007 hours, the destroyer, closing on Diaspro, was now at 1,000 metres and T.V. Donato decided to dive to 60 metres.

At 0102 hours, the submarine surfaced and immediately sighted a large steamer escorted by two corvettes at a distance of 3,000 metres.

At 0113 hours, four torpedoes were fired from the bow tubes, at a distance of 2,500 metres, at the steamer estimated to be of 15,000 tons. Her speed was intially estimated to 15 knots, but later corrected to 8 knots. It was then realised that the vessel was perhaps going at a slower speed causing the torpedoes to miss. Diaspro now reverted course.

At 0120 hours, the two stern torpedoes were fired at a range of 2,500 metres. Two hits were heard after 148 seconds but no such success is confirmed in British documents.

The target has not yet been identified.
Alberto Donato25 Jul 19430300(o) Near Point M3 (near Cape Vaticano).At 0300 hours, a hospital ship was sighted on a southerly course.
Alberto Donato25 Jul 19430310(o) Near Point M3 (near Cape Vaticano).At 0310 hours, two Italian steamers and a corvette were encountered on an opposite course. This was the convoy consisting of Viminale, Magliulo and Petsamo escorted by the torpedo boat Pallade, the corvette Gabbiano and the tug Forte and Tenax sailing from Messina for Naples. Pallade fired four star shells before recognising the submarine.
Alberto Donato26 Jul 1943022037.38.3 N, 16.38 E
At 0220 hours, an aircraft was seen and the submarine dived.
Alberto Donato26 Jul 19432133At 2133 hours, a MTB was sighted and Diaspro dived to 50 metres.
Alberto Donato27 Jul 19430243At 0243 hours, a MTB was sighted and Diaspro dived.
Alberto Donato27 Jul 1943040536.30 N, 16.09 E
At 0405 hours, an aircraft was seen and the submarine dived.
Alberto Donato27 Jul 19430440At 0440 hours, several aircraft were seen and the submarine dived.
Alberto Donato27 Jul 1943230836.20 N, 15.02 E
At 2308 hours, flares apparently dropped by an aircraft were seen and the submarine dived.
Alberto Donato28 Jul 19430232At 0232 hours, a MTB was seen and the submarine dived.
Alberto Donato28 Jul 1943171336.22 N, 14.40 E
At 1713 hours, an aircraft was seen when Diaspro was at periscope depth. She went deep.
Alberto Donato28 Jul 19432345At 2345 hours, a MTB was seen and the submarine dived.
Alberto Donato29 Jul 19430120At 0120 hours, a MTB was seen and the submarine dived to 50 metres.
Alberto Donato29 Jul 19432210At 2210 hours, a hospital ship was sighted and the submarine crash-dived, perhaps to avoid a collision.
Alberto Donato2 Aug 1943221539.07 N, 11.56 E
At 2215 hours, flares, apparently dropped by an aircraft, were seen and the submarine dived.
Alberto Donato18 Aug 1943005238.41 N, 15.20 E
At 0048 hours, two enemy destroyers were sighted, steering 149° at a distance of 8,000 metres.

At 0052 hours, Diaspro fired two stern torpedoes (533mm, S.I. type) at a distance of 5,000 metres. They missed.
Alberto Donato19 Aug 1943232338.42 N, 15.20 E
At 2319 hours, two destroyers were sighted steering 099°. Diaspro fired four torpedoes (533mm, G7e type) from her bow tubes at a range of 3,500 metres. Two were claimed to have hit. T.V. Donato believed he had sunk one and damaged the other.

At 0145 hours, an immobilised destroyer was sighted but the submarine had expended all her torpedoes and could not finish her off.

Unfortunately, the results were not confirmed. This was the last attack by an Italian submarine in the Mediterranean Theatre.
Alberto Donato4 Sep 19430820At 0820 hours, a buoy similar in shape to a mine was sunk by machine gun fire.
Alberto Donato7 Sep 19432130at 2130 hours, a hospital ship was seen at a distance of 3,000 metres.
Emilio Botta19 Aug 19440020-0152(o) Zante Island.Between 0020 and 0152 hours, Diaspro landed four agents on the island of Zante (one British officer, one Greek officer and two other ranks).
Emilio Botta20 Aug 19440100-0425(o) Cephalonia.Between 0100 and 0425 hours, Diaspro landed agents on the island of Cephalonia.

All Italian submarines