The Russian naval station Ismail along the Danube according to a CIA report dated 17 May 1948

An item reported that the harbour of Ismail served as a naval base with the northern part of Caslita Island, (on the 73rd kilometre above Ismail] considered to be used for the same purpose. North of Caslita Island and along the complete length of this island was in 1945 started with dredging which was nowadays still going on. In the last winter overwintered the Russian fleet at the northern part .

Source
The report was published on www.archive.org, document number CIA-RDP82-00457R001500460010-8