SM UC-18

SM UC-18 was a German Type UC II minelaying submarine or U-boat in the German Imperial Navy during World War I.
The U-boat was ordered on 29 August 1915 and was launched on 4 March 1916. She was commissioned into the German Imperial Navy on 15 August 1916 as SM UC-18. In 6 patrols UC-18 was credited with sinking 34 ships, either by torpedo or by mines laid. UC-18 was sunk by the British Q ship HMS Lady Olive on 19 February 1917.

Design

Like all pre-UC-25 Type UC II submarines, UC-18 had a displacement of when at the surface and while submerged. She had a length overall of, a beam of, and a draught of.
The submarine was powered by two six-cylinder four-stroke diesel engines each producing, two electric motors producing, and two propeller shafts. She had a dive time of 35 seconds and was capable of operating at a depth of.
The submarine had a maximum surface speed of and a submerged speed of. When submerged, she could operate for at ; when surfaced, she could travel at.
UC-18 was fitted with six mine tubes, eighteen UC 200 mines, three torpedo tubes, seven torpedoes, and one Uk L/30 deck gun. Her complement was twenty-six crew members.

Discovery

In March 2024, it was announced that the wreck of UC-18 had been discovered by a team of divers off the island of Guernsey at a depth of, some further west than the historical accounts of the battle described which was originally believed to have been west of the coast of Jersey.