German submarine U-16 was a Type IIB U-boat of Nazi Germany's Kriegsmarine that served during World War II. It was launched on 28 April 1936, under the command of Heinz Beduhn, with a crew of 23. The last of its four commanders was Kapitänleutnant Horst Wellner.
German Type IIB submarines were enlarged versions of the original Type IIs. U-16 had a displacement of when at the surface and while submerged. Officially, the standard tonnage was , however. The U-boat had a total length of , a pressure hull length of , a beam of , a height of , and a draught of . The submarine was powered by two MWM RS 127 S four-stroke, six-cylinder diesel engines of for cruising, two Siemens-Schuckert PG VV 322/36 double-acting electric motors producing a total of for use while submerged. She had two shafts and two propellers. The boat was capable of operating at depths of up to .
The submarine had a maximum surface speed of and a maximum submerged speed of . When submerged, the boat could operate for at ; when surfaced, she could travel at . U-16 was fitted with three torpedo tubes at the bow, five torpedoes or up to twelve Type A torpedo mines, and a anti-aircraft gun. The boat had a complement of twentyfive.
From 2 September 1939, until 25 October 1939, U-16 took part in the laying of mines in open water in and around the English Channel, to hamper allied shipping. On 28 September 1939, U-16 sank the Swedish 3,378 GRT Nyland. The 57 GRT French Sainte Claire was sunk by one of the mines laid by U-16 on 21 November 1939.
On 25 October 1939, U-16 was transiting the Dover Strait when it was attacked by and . Trying to avoid the depth charges from both ships, U-16 ran aground on the Goodwin Sands, an area that was notorious for both sides. U-16 was lost with all hands; other U-Boats were subsequently obliged to take the significantly longer route north of Scotland to the Western Approaches and the north Atlantic.