HMS 18 was one of a small number of boats sent to the Baltic by Winston Churchill, as First Lord of the Admiralty, to support the Russian navy in disrupting German shipments of iron ore from Sweden.
It was considered a great success, forcing the Germans to use convoys for the first time.
But in time the legacy was overlooked, earning it the unhappy nickname the ‘forgotten flotilla’
E18 left port in Reval, now Tallinn, the capital of Estonia, on the evening of 25 May. The next day she was reported to have torpedoed a German ship.
After that, there was silence.