Italian submarines in World War Two

Avorio (AV)

TypeCoastal / Sea going 
ClassPlatino 1 (24) 
Laid down 9 Nov 1940 Cantieri Riuniti dell'Adriatico, Monfalcone
Launched6 Sep 1941
Commissioned25 Mar 1942
End service
Loss date8 Feb 1943
Loss position37° 13'N, 6° 41'E
Fate Scuttled on 8th February 1943 north-west of Philippeville, Algeria, in position 37°13'N, 06°41.5'E after being forced to surface after being depth charges and being damaged by gunfire from the Canadian corvette HMCS Regina.


CommanderDate fromDate toCommand notes
C.C. Marco Revedin1 Apr 19426 Apr 1942
S.T.V. Silvestro Sergio Grandesso6 Apr 194210 Apr 1942
C.C. Emilio Gariazzo10 Apr 194227 Apr 1942
C.C. Mario Resio27 Apr 194220 May 1942
T.V. Mario Priggione20 May 194229 Jan 1943
T.V. Leone Fiorentini29 Jan 19439 Feb 1943

Ships hit

No ships hit by this submarine.

Patrols and events

 CommanderDateTimePortArr. dateArr. timeArr. portMilesDescription
11 Feb 19420945Monfalcone11 Feb 19421710MonfalconeExercises.

13 Feb 19420920Monfalcone13 Feb 19421735MonfalconeExercises.

14 Feb 19421000Monfalcone14 Feb 19421805PolaPassage Monfalcone-Pola.

16 Feb 19421000Pola16 Feb 19421805PolaExercises.

22 Feb 19420725Pola22 Feb 19422220PolaExercises.

23 Feb 19421055Pola23 Feb 19421620MonfalconePassage Pola-Monfalcone.

Revedin, Marco3 Apr 19420900Monfalcone3 Apr 19421320MonfalconeExercises.

Grandesso, Silvestro Sergio6 Apr 1942Monfalcone10 Apr 1942MonfalconeIn reserve, change in command.

Gariazzo, Emilio10 Apr 1942Monfalcone27 Apr 1942MonfalconeIn reserve, change in command.

Gariazzo, Emilio24 Apr 19420910Monfalcone24 Apr 19421230MonfalconeExercises.

Resio, Mario27 Apr 1942Monfalcone20 May 1942MonfalconeChange in command.

Priggione, Mario25 May 19420900Monfalcone25 May 19421700MonfalconeExercises.

Priggione, Mario27 May 19420800Monfalcone27 May 19421900MonfalconeExercises.

Priggione, Mario1 Jun 19420800Monfalcone1 Jun 19421225VenicePassage Monfalcone-Venice.

Priggione, Mario2 Jun 19421140Venice2 Jun 19421315VeniceExercises.

Priggione, Mario5 Jun 19420845Venice5 Jun 19421450PolaPassage Venice-Pola.

Priggione, Mario9 Jun 19421200Pola9 Jun 19421615PolaExercises.

Priggione, Mario12 Jun 19420730Pola12 Jun 19421625PolaExercises.

Priggione, Mario15 Jun 19420625Pola15 Jun 19422030PolaExercises escorted by the torpedo boat T.3.

Priggione, Mario18 Jun 19420550Pola18 Jun 19421945PolaExercises.

Priggione, Mario22 Jun 19420635Pola22 Jun 19421515PolaExercises.

Priggione, Mario28 Jun 19421410Pola1 Jul 19421120NaplesPassage Pola-Naples with the submarine Granito.

Priggione, Mario3 Jul 19420825Naples3 Jul 19421600NaplesExercises.

Priggione, Mario4 Jul 19420810Naples4 Jul 19421420NaplesExercises.

Priggione, Mario5 Jul 19420820Naples5 Jul 19421400NaplesExercises.

Priggione, Mario9 Jul 19420915Naples9 Jul 19421630NaplesExercises.

Priggione, Mario10 Jul 19420825Naples10 Jul 19421540NaplesExercises.

Priggione, Mario12 Jul 19420825Naples12 Jul 19421340NaplesExercises.

Priggione, Mario13 Jul 19420835Naples13 Jul 19421555NaplesExercises.

Priggione, Mario14 Jul 19420840Naples14 Jul 19421500NaplesExercises.

Priggione, Mario16 Jul 19420930Naples16 Jul 19421315NaplesExercises.

Priggione, Mario17 Jul 19420830Naples17 Jul 19421534NaplesExercises.

Priggione, Mario18 Jul 19420845Naples18 Jul 19421645NaplesExercises.

Priggione, Mario19 Jul 19420840Naples19 Jul 19421840NaplesExercises.

Priggione, Mario21 Jul 19420840Naples21 Jul 19421540NaplesExercises.

Priggione, Mario22 Jul 19420840Naples22 Jul 19421516NaplesExercises.

Priggione, Mario24 Jul 19420747Naples24 Jul 19420935NaplesExercises.

Priggione, Mario27 Jul 19421425Naples27 Jul 19422305NaplesExercises.

Priggione, Mario29 Jul 19421440Naples30 Jul 19420031NaplesExercises.

Priggione, Mario3 Aug 19420725Naples3 Aug 19421130NaplesExercises.

Priggione, Mario4 Aug 19420905Naples5 Aug 19421030CagliariPassage Naples-Cagliari.

1Priggione, Mario11 Aug 19421726Cagliari17 Aug 19421137Cagliari?Patrolled off northern Tunisia, between 37°20' N and 38°00' N and between 09°40' E and 10°00' E, operating against the PEDESTAL convoy.
  12 Aug 1942155537° 35'N, 9° 50'E
(0) Approximately.
At 1555 hours, a submarine was sighted.
  12 Aug 1942170837° 35'N, 9° 50'EAt 1708 hours, an enemy force of three battleships who appeared to be American, several steamers and destroyers were sighted at at distances varying from 12,000 to 18,000 metres.

Avorio attempted to close for an attack but two destroyers turned toward her. At 1725 hours, she submerged and, five minutes later, four depth charges exploded. The submarine escaped by diving to 100 meters and heard a total of 180 depth charges.

2Priggione, Mario18 Aug 19420027Cagliari19 Aug 19421323Trapani?Patrolled off north coast of Tunisia, between 37°20' N and 37°50' N, and between 09°20' E and 10°20' E.
  18 Aug 1942025538° 51'N, 9° 29'EAt 0255 hours, as Avorio was leaving Cagliari, a submarine was a sighted at a distance of 500 metres steering 050°. T.V. Mario Priggione prepared the two stern tubes but hesitated to attack as it could have been an Italian submarine and finally aborted.

The submarine was HMS P 211 (Commander Ben Bryant, DSC, RN) (later to be named HMS Safari. Avorio was not noticed.
  18 Aug 19420600At 0600 hours, an Italian tanker, believed to be Perseo, was sighted at a distance of 10,000 metres. Avorio closed and made repeated visual signals but the vessel escaped at full speed. The submarine finally closed to 4,500 meters and transmitted in clear a warning that she had sighted a submarine 38°51'40" N, 09°29'40" E [HMS P 211] but the vessel did not respond and appeared to be arming her stern gun. At 0647 hours, Avorio gave up and returned on her original course. Three hours later Perseo was torpedoed and sunk by HMS P 211.

Priggione, Mario22 Aug 19420515Trapani23 Aug 19420055CagliariPassage Trapani-Cagliari.

Priggione, Mario25 Aug 19420825Cagliari25 Aug 19421115CagliariExercises.

Priggione, Mario28 Aug 19420630Cagliari28 Aug 19420840CagliariExercises.

Priggione, Mario5 Sep 19420750Cagliari5 Sep 19421110CagliariExercises.

Priggione, Mario13 Sep 19422100Cagliari15 Sep 19420800AugustaPassage Cagliari-Augusta.

Priggione, Mario26 Sep 19420830Augusta26 Sep 19421305AugustaExercises.

Priggione, Mario3 Oct 19420855Augusta3 Oct 19421315AugustaExercises.

Priggione, Mario15 Oct 19420840Augusta15 Oct 19421400AugustaExercises.

Priggione, Mario22 Oct 19420900Augusta22 Oct 19421245AugustaExercises.

Priggione, Mario5 Nov 19421630Augusta6 Nov 19421633TrapaniPassage Augusta-Trapani.

3Priggione, Mario7 Nov 19421551Trapani8 Nov 19420200TrapaniSailed for patrol, but very quickly recalled for new instructions.

3bPriggione, Mario8 Nov 19420245Trapani13 Nov 19421630CagliariSailed for patrol off the north coast of Tunisia, between 37°18'N and 37°41'N, and between 09°54'E and 10°15'E and then ordered on 9th November to an area between 37°00'N and 37°20'N, and between 06°20'E and 06°40'E. Arrived at dawn on 9th November at the entrance of the Bay of Bone. Uneventful. The submarine heard H.E. but sighted nothing. Because she was leaking fuel, the submarine had to return to base.

4Priggione, Mario16 Nov 19421817Cagliari26 Nov 19420940Cagliari?Sailed for patrol between 37°40' N and 38°00' N, and between 07°40' E and 08°00' E. On the evening of the 19th, she made a reconnaissance of Bone. On 20th November, she was moved to an area between 37°20' N and the Algerian coast, and between 07°20' E and 07°40' E.On the evening of 23rd November, she made a reconnaissance of the Bay of Bougie.
  17 Nov 19420625At 0625 hours, a submarine was observed to be diving. Avorio also submerged at 0649 hours.
  19 Nov 1942022137° 15'N, 7° 39'EAt 0221 hours, a corvette was sighted at a range of 5,000 metres. T.V. Mario Priggione did not try to attack the enemy vessel, fearing the presence of other enemy warships.
  22 Nov 19420234-0317At 0234 hours, the Italian submarine Argo was encountered and recognition signals were exchanged. This was followed by vocal exchange between the two commanders.
  24 Nov 1942015436° 42'N, 5° 11'EAt 0116 hours, a dark shadow was sighted at a distance of 800 metres at the limit of a rain squall.

At 0147 hours, the submarine surfaced to close and recognised the vessel to be a one-funnel destroyer with two guns forward.

At 0154 hours, three torpedoes (a fourth misfired) were fired from bow tubes at a range of 600 metres and Avorio dived. After 40 seconds, almost simultaneous explosions were heard. The submarine surfaced at 0342 hours with nothing on the horizon.

Allied records have not confirmed this attack.

Priggione, Mario10 Dec 19421350Cagliari10 Dec 19421635CagliariExercises.

Priggione, Mario11 Dec 19421020Cagliari11 Dec 19421245CagliariExercises.

Priggione, Mario13 Dec 19421415Cagliari13 Dec 19421655CagliariExercises.

Priggione, Mario14 Dec 1942Cagliari14 Dec 1942CagliariExercises.

Priggione, Mario22 Dec 19421355Cagliari22 Dec 19421620CagliariExercises.

Priggione, Mario23 Dec 19420905Cagliari23 Dec 19421015CagliariExercises.

Priggione, Mario30 Dec 19420840Cagliari30 Dec 19421050CagliariExercises.

5Priggione, Mario2 Jan 19431210Cagliari2 Jan 19431505CagliariSailed for patrol between 37°30' N and the Algerian coast, and between 06°40' E and 07°00' E but was very quickly recalled.

5bPriggione, Mario4 Jan 19430418Cagliari11 Jan 19430750Cagliari?Sailed for patrol between 37°40' N and 38°00' N, and between 09°20' E and 09°40' E. On 7th January, she was ordered to an area between 37°20' N and the Algerian coast, and between 04°20' E and 04°40' E.
  9 Jan 19432347
0016/10 (e)
37° 43'N, 4° 45'EAt 2347 hours, Avorio was steering 090°, when an aircraft, believed to be a Liberator, illuminated her with a projector (Leigh Light) and dropped four bombs. The submarine crash-dived, but the diesel exhaust pipe could not be immediately shut and a quantity of water entered the submarine and the dive was not stopped before a depth of 97 metres had been reached.

The submarine had to surface again, but the aircraft with the projector was sighted just above her at a height of 50 metres, forcing her to crash-dive again. It was noticed that the torpedo cap of tube no. 6 (stern) was not shut properly but this had not caused a leak even though the submarine had reached a depth of 100 metres . However, it was difficult to keep the boat down at a safe depth and Avorio had to surface again. Some 30 tons of water had entered the submarine and it was not possible to start the dielsels, so electric motors had to be used. The aircraft was still circling around.

At about 0010 hours on 10th January the aircraft returned, still using its projector and, dropped four bombs. The nearest fell 10 metres from the submarine, starboard aft of the forward hydroplanes. The bomber was observed to fire with its stern gun but the burst fell short of Avorio who was firing back with her three machine-guns and apparently hit the projector. The submarine was slightly damaged and had to abort her mission.

The attack was made by Wellington 'W' (HX.531) of 179 Squadron, piloted by Flight Sergeant A.D.S. Martin. It had detected the submarine by radar at a range of 11 miles. It was steering 090° at 4 knots. The bomber attacked at 0016 hours, dropping four Mark XI Torpex depth charges from a height of 300 feet set at shallow depth and two flame floats.
  10 Jan 19430310At 0310 hours, the repatriation ships Giulio Cesare and Duilio were sighted at a distance of 1,000 metres. Avorio turned away.
  10 Jan 1943103538° 35'N, 6° 20'EAt 1035 hours, a Sunderland was sighted at a range of 1,000 metres. Avorio crash-dived but the acid vapours caused by the damages incurred on 9th January forced the submarine to emerge at 1750 hours and continue her return passage on the surface.

Priggione, Mario14 Jan 19430847Cagliari14 Jan 19431056CagliariExercises.

Priggione, Mario15 Jan 19430835Cagliari15 Jan 19431102CagliariExercises.

6Priggione, Mario20 Jan 19430220Cagliari24 Jan 19430815Cagliari?Patrolled off Bougie.
  21 Jan 19432350At 2350 hours, a submarine was sighted at a distance of 3,000 metres. Avorio dived
  23 Jan 1943035037° 27'N, 6° 08'E
(0) Approximately.
At 0350 hours, a submarine was sighted at 5,000 metres. Avorio dived.

Priggione, Mario28 Jan 19431345Cagliari28 Jan 19431606CagliariExercises.

Priggione, Mario30 Jan 19431404Cagliari30 Jan 19431655CagliariExercises.

7Fiorentini, Leone6 Feb 19431340Cagliari9 Feb 19430510SunkSailed for patrol between 37°40'N and the African coast and between 06°20'E and 06°40'E. Sunk off Bougie by HMCS Regina. One officer and twenty-six ratings were picked up, twenty were killed or missing (three officers including Fiorentini, the First Lieutenant and seventeen ratings). At 2320/8, the submarine sighted Regina, who was escorting stragglers of the M.K.S.8 convoy, when she was only 600 meters away. Avorio crash-dived but was depth-charged at 2323 and forced to surface. After a brief attempt at resistance (only a few MG rounds could be fired), she was abandoned. A tug took her in tow, but she sank at 0510 in 37°13'N, 06°41'E.
  8 Feb 19430015AAt 0015A hours, the minesweeper HMS Rothesay escorting LSTs, attacked a U-boat. This was believed to have been Avorio.
  8 Feb 19432310
(e) 37° 13'N, 6° 41'E
At 2310 hours, the corvette HMCS Regina, escorting a convoy, detected a submarine by radar at a range of 6,200 yards. She closed the range but briefly lost contact as the submarine submerged and regained it by ASDIC at 2317 hours when she was only 600 metres distant.

This was Avorio and she had crash-dived. At 2323 hours, Regina dropped a pattern of ten depth charges set at shallow depth. The submarine was then observed trying to escape on the surface and the corvette opened fire with two bridge oerlikons soon joined by the 4" gun. The submarine replied with a twin Breda machine-gun but was soon silenced and abandoned.

At 0345 hours on the 9th, the tug Jaunty took her in tow but she sank at 0510 hours. One officer and twenty-six ratings were picked up. Twenty were killed or missing: three officers including T.V. Leone Fiorentin and the First Officer and seventeen ratings. A number of documents were recovered from this submarine which helped British Intelligence have a pretty accurate view of Italian submarine operations in January 1943.

80 entries. 71 total patrol entries (7 marked as war patrols) and 15 events.

All Italian submarines