Naval mine ship, HMHS "Britannic", which was the sister ship of the RMS "Titanic." During World War II, the U-boat fleet, which dominated much of the battle of the Atlantic, was small at the beginning of the war and much of the early action by German forces involved mining convoy routes and ports around Britain. German submarines also operated in the Mediterranean Sea, in the Caribbean Sea, and along the U.S. coast. Initially, contact mines (requiring a ship to physically strike a mine to detonate it) were employed, usually tethered at the end of a cable just below the surface of the
German hospital ship Ophelia by German U-boat "UB-10" off the Boulogne light vessel. German hospital ship Ophelia The Ophelia was a steamship originally built by a German shipping company, but requisitioned for use as a hospital ship by the Imperial German Navy during the First World War. After being viewed acting suspiciously, the "Ophelia" was boarded on 17 October 1914 and seized by the Royal Navy for violating Hague Convention X of 1907 concerning hospital ships. After her seizure, she operated in British service as SS "Huntley" until sunk in December 1915. On 17 October 1914 a number of German torpedo boats were destroyed