SM UB-23 [SEP] vessel class
SM UB-23
SM "UB-23" was a German Type UB II submarine or U-boat in the German Imperial Navy () during World War I. The U-boat was ordered on 30 April 1915 and launched on 9 October 1915. She was commissioned into the Imperial German Navy on 13 March 1916 as SM "UB-23". The submarine sank 49 ships in 21 patrols for a total of . On 26 July 1917, "UB-23" was badly damaged by a depth charge attack by off the Lizard; she put
SM UB-123
SM "UB-123" was a German Type UB III submarine or U-boat in the German Imperial Navy () during World War I. She was commissioned into the German Imperial Navy on 6 April 1918 as SM "UB-123".
She torpedoed and sunk a vessel operated by the City of Dublin Steam Packet Company on 10 October 1918, shortly after the new German Government had asked President Wilson to negotiate an armistice. "Leinster" went down just outside Dublin Bay. Over 500 people perished in the sinking