Operation Bona

By Andrea Piccinotti

After the Allied landing in Morocco, and the Axis’ occupation of Tunisia, the epicenter of naval warfare in the Mediterranean had definitely shifted to the West. German and Italian political pressure forced Supermarina into preparing plans for an operation against enemy traffic between Bougie and Bona. Since November 1942, the Italian armed trawler “Corrispondende Omega,” flying the French flag, had begun an adventurous study of Allied naval traffic along the Algerian and Tunisian coastlines.

This action was meant to be mostly demonstrative and of little military value; it was to prove the offensive determination of the Regia Marina, especially in the eyes of the German ally. The serious shortage of oil fuel, by now at its worst, would have made the mission impossible to repeat. The only active naval force at the time included the two surviving heavy cruisers, Gorizia and Trento, assigned to the III Division. All other ships were locked in port for several months to save the little oil fuel left in expectation of the final sortie at sea of the three modern battleships. Also, since March 1943, the shortage of destroyer escorts was very serious, and the seven units left of the “Poeti” and “Soldati” class were withdrawn from the Tunisian slaughterhouse for some rest and training. It was therefore decided that the cruiser division would be escorted by only two units, and in case of emergency, they would have done without them.

The mission was naturally subject to the availability of an effective aerial reconnaissance, and the element of total surprise, in order to avoid direct confrontation with superior enemy forces. Weighing anchor from La Maddalena, the cruisers would have navigated South, hence reaching the assigned area at dawn, thus beginning patrol. Here the plan was twofold:

1. If the Italian units had been able to encounter an enemy convoy, probably while it was approaching the port of Bona, they would have destroyed it and then quickly returned to Italy.
2. In case of failed encounter with the convoy, the two cruisers would have navigated within sight of the enemy base, used by enemy cruisers, at a speed of 30 knots, keeping always away from shoals and bombarding the unit at anchor. Immediately after, they would have returned at full speed to Italy.

The whole plan was based on the assumption that the threat posed by the Allied air force could be contained by the Regia Aeronautica and the Luftwaffe. In fact, during the first months of 1943, Allied aerial attacks against Axis convoys to Tunisia were conducted by a few British Squadrons based in Malta and Libya. These attacks had never caused painful losses and were not a serious threat to ships sailing at high speed. In early April the situation changed quite dramatically with the arrival of the new American bombers, which doubled the menace thanks to the introduction of high level formation bombing by 50 to 60 aircrafts which laid real carpets of bombs known as “carpet bombing”.

The situation at night was quite different; the British had refined their night attack techniques, reaching a high level of expertise which the Regia Aeronautica and the Luftwaffe could not counteract at all. The Regia Marina paid particular attention to the electronic equipment of the ships involved in this mission. First, in addition to the installation of a German radar detector of the type Metrox, it was thought to equip the cruiser Trento with one of the latest Italian radars of the type E.C. 3 Gufo, but later it was realized that such installation would have required too much time. Due to mechanical problems, and considering that the cruisers would have had to enter a naval repair facility, the mission would have been delayed too much. Later, it was thought to provide the cruisers with the escort of destroyers furnished with radar equipment: first the famous Legionario, which had a German “Dete”, then the Oriani, which was equipped with similar equipment.

Delays linked to the fine tuning of the equipment, and the need to operate during a night without lunar light, forced Supermarina to delay the mission from the middle of March to April. The time lost was not wasted; the Italian cruisers completed a long ballistic exercise on the 18th of March. This was an incredible luxury for the times, since the last time the fleet had gone to sea for practice dated back to the 19th of October, 1942.

Suddenly, on the 10th of April, less than 48 hours before receiving departure orders from Supermarina, the island of La Maddalena was, for the first time, bombed by the Allied air forces. The raid, conducted by 136 aircrafts, was extremely accurate and had disastrous effects: the cruiser Trieste, after a few hours of agony, sank with the hull completely devastated. The cruiser Gorizia received serious damage, which forced her commander to beach the ship in shallow waters. Later, the Gorizia would be rescued and sent to La Spezia where it was lost on September 8th, 1943.

The loss of the only active naval force caused an indefinite postponement of the operation. Immediately after, the Regia Marina began hunting for the “traitor”, since such a close coincidence was not conceived possible. In reality, the Allied forces feared a naval incursion against their convoys and had kept La Maddalena under strict surveillance. The sortie at sea of March 18th had not eluded the Allied forces, who decided to speed up planning for their action, thus preempting the Italian one.