SM U-103[Note 1] was an Imperial German Navy Type U 57 U-boat that was rammed and sunk by HMT Olympic during the First World War.

Claus Rücker and sank eight ships totalling 15,467 gross register tons (GRT) before being lost in the English Channel on 12 May 1918.

[3] In the early hours of 12 May 1918, the surfaced U-103 sighted Olympic, the older sister of RMS Titanic, which was carrying US troops to France.

But there was not enough time before the port propeller of Olympic sliced through the submarine's pressure hull just aft of its conning tower.

Its deep location makes it largely inaccessible to divers but the wreck was surveyed and identified by a remotely operated underwater vehicle in 2012.