Harbour of Saloniki, Greece protected by beam barrier against submarines ccording to the Kriegsnachrichten No. 61 of the Chef des Admiralstabes der Marine dated 2 July 1918

An item referring to a reliable agent reported that mit June the harbour of Saloniki was protected by a beam barrier against submarines. Regurlay was the harbour visited by an armed motor boat of the guard flotilla stationed in the Gulf of Naples.

Source

Bundesarchiv RM-40-622