On 29 April, "Sickle" departed Malta to patrol in the Aegean Sea, where she sighted a German transport escorted by three destroyers, but lost sight of them in the fog on 7 May. The next day, the boat sank three Greek sailing vessels with demolition charges and by ramming in the Doro Channel. She initially attacked them on the surface with her deck gun, but it jammed after firing four rounds, so "Sickle" boarded the first ship, a caïque flying the Greek flag with the German occupation pennon. The ship was carrying a cargo of oranges and lemons, and sailors from "Sickle" brought a thousand of these to their submarine as an addition to their diet, then holed the caïque's hull, sinking it. The next two ships did not carry any salvageable cargo, and "Sickle" sank one with demolition charges and the other by ramming. On 11 May, "Sickle" surfaced and bombarded an enemy radar station with her three-inch deck gun; 17 rounds hit their target but the enemy returned fire four minutes later, wounding three men, including "Sickle"s captain and forcing her to submerge. Shortly after midnight on 13 May, the boat surfaced and sank the German sailing vessel "Fratelli Corrao" with gunfire. Two days later, she returned to Malta.