At 01.24 hours on 22 August 1943, U-24 fired with her 20mm gun and a machine-gun at the Soviet patrol craft SKA-0188, which had two motorboats in tow. The U-boat reported a tug of 10 tons sunk, but apparently the patrol craft returned fire, dropped the tow lines and escaped undamaged. The DB-36 was then attacked by gunfire and hand grenades, three men were captured. At 02.52 hours, the other motorboat DB-37 was sunk by gunfire and demolition charges, the crew of three men were captured. The U-boat then tried to tow the first boat, but it had to be sunk by demolition charges at 03.31 hours. Four of the six prisoners had been wounded, they were all landed in Feodosia on 23 August.