SM U-34 was a German U-Boat of World War I. Launched on May 9, 1914, U-34 sank a total of 119 ships during 17 combat patrols, while damaging another 5 ships. The vessel had three commanders during its time: Claus Rucker, Johannes Klasing, Wilhelm Canaris, and Klasing again, in that order. On October 18, 1918, U-34 sailed for the last time, disappearing with all 38 crew members lost. Although it was claimed that she was depth charged and sunk near Gibraltar by HMS Privet on November 9, 1918, it is believed that the U-Boat had been lost prior to that, but it has never been confirmed one way or the other.