Soviet submarines lying in the harbour of Ventspils, Latvia according to a Cia report dated 19 May 1953

An item reported the presence of 3 Soviet submarines in the southern part of the harbour of Ventspils, Latvia. Two dark grey painted submarines with sharp saw-like bows were moored together and seemed to be identical. On the foredeck before the conning tower was a gun mounted and stretching from the coning towers was an extended tube around a meter above the water level high and thick like a man’s leg. The purpose was unknown. The third grey painted submarine moored on distance of around 30 metres of the two other submarines was smaller. On the conning tower was a gun mounted, All three submarines seemed to be based on German designs and built in the Soviet Union.

Source
The report was published on www.archive.org, document number CIA-RDP80-00810A000700260003-3