German aircraft sighed Russian small naval units at Ywisk according to the German War Diary of Admiral Black Sea dated 4 September 1943

An item reported that on 07:36 in the partially by clouds covered harbour of Ywisk [Yeysk at the shore of the Taganrog Gulf or Sea of Azov?] 5 motor gunboats and around 20 boats were sighted.

Source

German War Diary of Admiral, Black Sea 1-30 September 1943. Published by Department of the Navy. Washington, 1955.