SM UC-21

SM UC-21 was a German Type UC II minelaying submarine or U-boat in the German Imperial Navy (Kaiserliche Marine) during World War I. The U-boat was ordered on 26 August 1915 and was launched on 1 April 1916. She was commissioned into the German Imperial Navy on 12 September 1916 as SM UC-21. In 11 patrols UC-21 was credited with sinking 100 ships, either by torpedo or by mines laid. UC-21 disappeared after departing Zeebrugge for the Bay of Biscay on 13 September 1917.

In July 2013, archaeologists found the remains of 44 submarines, including UC-21, off the United Kingdom’s southern and east coasts, near the county of Suffolk. The find was made up mostly of vessels from the German Imperial Navy dating to World War I. Der Spiegel reported divers located 41 German U-boats, and three of English submarines, found at depths of up to 50 feet, off England’s southern and eastern coasts.