U4
29 Aug 190917 Oct 1914 in action against French squadron attacking the Bocche. Sank Albanian sailing ship Fiore del Mare 28 Nov 1914.
Completed major reconstruction on 26 Apr 1915. 09 Jun 1915 torpedoed and seriously damaged British cruiser Dublin. 28 Jun 1915 found downed flying boat L43 and towed her to the Bocche. 18 Jul 1915 torpedoed and sank Italian armoured cruiser Giuseppe Garibaldi.
02 Aug 1916 unsuccessfully attacked French-Italian destroyer group. 14 Aug 1916 torpedoed Italian Q-ship Pantelleria south of Taranto.
30 May 1917 torpedoed French auxiliary cruiser Italia 30 nm off Taranto.
To France; b/u.