The official war record of the Italian Navy states: “The most painful loss of the month of August 1941 was, undoubtedly, the SS Esperia of over 11,000 t., sunk by a submarine when it was already in sight of the port of Tripoli.” The official Italian war record, as published in “La Difesa del Traffico con l’Africa Settentrionale” (The Protection of the Traffic with North Africa) reads:

“The convoy left Naples on the 19th of August at 02:00 AM, and included the passenger ships Marco Polo, Esperia, Neptunia and Oceania and it was routed east of Malta (Sicilian Channel, Island of Pantelleria, Kerkennah Islands). Starting from its departure in Naples, the convoy was escorted by the destroyers Vivaldi (lead) Da Recco, Gioberti, Oriani. The Vivaldi had aboard, for the occasion, Rear Admiral Amedeo Nomis di Pollone, Commander at Sea for the mission. After 1:30 PM, the convoy was reinforced by the torpedo boat Dezza and, after 2:50 PM at the beginning of the more dangerous section of the crossing slightly to the north of Marettimo, by the destroyers Maestrale, Grecale and Scirocco.

Moreover, during daylight navigation, both in the Tyrrenhian and in the Sicilian Channels, the convoy was escorted by airplane S. 79 and CR 42 and, in the later afternoon of the 19th, by seaplanes Cant Z 506 for antisubmarine protection. From 5:20 PM to 6:30 PM, north of Pantelleria, the convoy endured two successive underwater attacks, and both times the torpedoes, timely sighted by the convoy’s lookouts, were avoided with prompt maneuvers. The Vivaldi and the Gioberti pursued the enemy submarines for approximately one hour without appreciable results.

The 20th of August at 01:00 AM, the destroyers Maestrale and Grecale returned to port to refuel, and the destroyers Vivaldi, Da Recco, Oriani, Gioberti and Scirocco, along with the torpedo boat Dezza were left in charge of defending the convoy. At 8:30AM, when the convoy was entering the safe channel to Tripoli (a navigational path leading to port and free of mines), the escort was augmented with the arrival of the torpedo boat Partenope and two MAS.

After daybreak, Cant Z 501s had also resumed circling over the naval formation, providing for submarine protection. During the approach to Tripoli, the convoy was preceded by a group of mine sweepers that had already searched the approaching route for several hours. The Italians, undoubtedly, had taken all the necessary precautions to guarantee the safety of their vessels, but unfortunately not even such a large deployment of defensive measures succeeded in avoiding the convoy being attacked by a British submarine.

From British documentation, it turns out that in those days there were three submarines in ambush in the area immediately surrounding the “safe” route to Tripoli: UNIQUE (Lieutenant-Commander R.D. Cayley, D.S.O.), P. 32 (Lieutenant D.A.B. Abdy) and P. 33 (Lieutenant R.D. Whiteway-Wilkinson, D.S.C.). The fact was not exceptional, as English submarines were generally in ambush in the special points of the Italian traffic with Libya. The boats P. 32 and P. 33 were both lost, but the UNIQUE, avoiding the convoy’s defensive screen, succeeded in positioning itself close enough to the MV Esperia to torpedo it.

Admiral Nomis di Pollone, Commander at Sea, reported:
"At 10:20 AM of August 20, the convoy including the SS Marco Polo and Esperia, and the MV Neptunia and Oceania, escorted by the destroyers Vivaldi, Gioberti, Da Recco, Oriani, Scirocco, the Torpedo boat Dezza and two MAS from Tripoli were preceded by the pilot, torpedo boat Partenope, at a point 11miles for true bearing 318° from the beacon of Tripoli, and proceeded at a speed of 17 knots on safe route n. 3 (true course 138). The formation was flown over by aerial defenses composed of 2 Cant Z 501 and 2 fighters.

All the units in the convoy, excluding the pilot, were zigzagging and although the convoy was already on the safe route, it had to be maintained in formation due to the frequent presence of submarines near the Libyan coast. Upon initiating the approaching procedures, the Oriani launched six depth charges to scare off any enemy.

At 10:20 AM, without having sighted the periscope, the Esperia detected the wave of a torpedo to the left perfectly aiming at the ship. Before it was possible to execute any evasive maneuver, the Esperia was hit by a torpedo forward of the bridge; the explosion was immediately followed by the explosion of two others torpedoes, one to the center of the ship (boiler room) and the other one aft. The Esperia immediately began leaning to the left; it remarkably lost headway very quickly, coming to a stop approximately 40° to the left of the original course. The other units in the convoy, as prescribed, continued on due course to port and the Marco Polo raised the signal “I T” (follow me) increasing to full speed ahead. Such a quick decision by the convoy’s commander was very opportune since going astray from the prescribed route could have brought the convoy in dangerous waters due to defensive mine fields.

In the meantime, aboard the Esperia the crew was trying to put in sea the lifeboats, but the maneuver succeeded only partially because of the excessive list and the residual headway of the ship. At 10:31 the Esperia completely pulled down to the left side and sank with the prow low without generating too much gurgle.

At first the explosions against the side of the Esperia were of indeterminate nature, since an observer from any other ship could have assumed a mine, as well as a torpedo, or perhaps bombs from a high flying airplane. A few minutes later, bombs dropped at about 1,000 meters to the left of the Esperia made everyone realize that the planes were after a submarine and that torpedoes had caused the explosions.

I then ordered the Oriani, Scirocco and Dezza to approach the area of the shipwreck and begin the rescue operations, while the Gioberti proceeded with the MAS to give hunt to the submarine, assisted later on by the Da Recco, which at first I had designated to accompany the convoy on the escape route.

At 12:00 three tugs and some motor-sail boats from Tripoli reached the place. Meantime, since the greater part of the shipwreck had been recovered by the units in the convoy, I ordered these units to direct for Tripoli in order to avoid further risks of attack by submarine, leaving in place the Dezza to protect the crafts from Marilibia (Italian Naval Command in Libya) .

People rescued by the:
Vivaldi 76
Oriani 254
Scirocco 471
Dezza 61
Naval units from Tripoli 277
Total 1,139

Observations and proposals - the circumstances described in which the attack has taken place induce us to assume that the submarine executed a launch at a short distance, probably utilizing hydrophones. It is possible that the enemy knew of the arrival of the convoy, since it had been attacked the previous evening by a submarine near Pantelleria with the launch of two torpedoes... ".

The SS Marco Polo, and MV Neptunia and Oceania, as previously said, after the attack of the Unique, continued on to Tripoli entering port at 12:30 PM. They quickly carried out the disembarkation of men and materials and then the three cargo vessels left Tripoli at 5:00 PM of the 21st and reached Naples under the escort of the destroyers Vivaldi, Da Recco, Oriani, Gioberti, Scirocco."