'Cigno' was an Italian convoy from Naples to Tunis involved in a naval action to the south-west of Marettimo island, off the western tip of Sicily (15/16 April 1943).

The action involved British naval forces and two Italian torpedo boats escorting the 4,200-ton transport Belluno, and was fought at a time when the Allies were making a major air and sea effort to prevent supplies flowing to and men being evacuated from the final Axis lodgement in North Africa, and thereby facilitating the isolation and final defeat of Generaloberst Hans-Jürgen von Arnim’s Heeresgruppe 'Afrika'. The action was thus part of the daily aerial, naval and submarine campaign mounted by the Allies against Axis forces, in the spring of 1943, in order to achieve a complete naval and air supremacy around North Africa and Sicily.

By April 1943, Axis merchant ship losses (an average of 3.3 ships per day) had reached an almost insupportable level, and while the Axis supply route was comparatively short between Sicily and North Africa, Allied air and naval superiority had by this time made the assembly and passage of large convoys impossible. In combination with an acute and worsening fuel shortage, this persuaded the Italians to make use of fast destroyers and/or torpedo boats to escort small numbers of cargo ships. However, the convoys could average only 8 to 10 kt as the Italians had already lost virtually all of their higher-speed merchant shipping in their efforts to keep reinforcements, weapons and supplies flowing to the Axis forces involved in the 'Campaign for the Western Desert'.

One of these small convoys, comprising the ex-French transport Belluno escorted by the torpedo boats Cigno and Cassiopea, departed Naples bound for Tunis on 15 April. A supplementary escort force, comprising the torpedo boats Climene and Tifone, was scheduled to depart two hours later from Trapani to reinforce the convoy. On 02.38 on 16 April the leading escort, commanded by Capitano di Vascello Carlo Maccaferri, sighted the approach of two British destroyers, Pakenham and Paladin, under the command of Commander Basil Jones. This was one of the few night engagements in the Mediterranean in which the British failed to take their opponents by surprise, a fact which became decisive to the outcome of the action. However, the firepower of Pakenham and Paladin was superior to that of the Italian torpedo boats: the British destroyers each carried five 4-in (101.6-mm) guns, whereas the Italian torpedo boats each carried just three 100-mm (3.94-in) guns.

The first vessel to suffer the effects of gunfire was Cigno, which was almost immediately stopped in the water but nonetheless continued to fire on the British ships until it was sunk by a torpedo with the loss of 103 men. Despite being hit several times, Cassiopea fought back with a torpedo launched against Paladin and gunfire against Pakenham, which was hit at least six times on the port side and sustained serious damage in the engine room, where at several men were scalded as a boiler exploded. Nine men were killed, and a tenth man died of his wounds two days later. Paladin was also damaged by shell splinters.

During the clash, Belluno managed to slip away toward the north-east, where the rear escorting force was coming up in total ignorance of events. Belluno reached her destination safely some hours later.

Meanwhile, the British ceased fire and withdrew. Almost totally disabled, Cassiopea was assisted by Climene, which took her in tow back to Trapani and thence to Taranto for repairs.

After trying to reach Malta on the limited power of an auxiliary engine, Pakenham broke down off Sicily and Paladin, unable to take her in tow, then sank her sister with a torpedo.

In the 'Battle of the Cigno Convoy', the Italian casualties were one of their two torpedo boats sunk and the other damaged, and between 100 and 120 men, while those of the British were one of their two destroyers scuttled and the other damaged, and 10 men killed.