German submarine U-733 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. The submarine was laid down on 13 October 1941 at the Schichau-Werke yard at Danzig, launched on 5 September 1942, and commissioned on 14 November 1942 under the command of Oberleutnant zur See Wilhelm von Trotha.
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-733 had a displacement of when at the surface and while submerged. She 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 Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of for use while surfaced, two AEG GU 460/8âÂÂ27 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-733 was fitted with five torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one SK C/35 naval gun, 220 rounds, and two twin C/30 anti-aircraft guns. The boat had a complement of between forty-four and sixty.
On 8 April 1943, U-733 collided with Vorpostenboot V 313 outside Gotenhafen port and sank without fatalities. The next week, U-733 was raised and repaired in the Schichau yard. On 15 December 1943, U-733 was re-commissioned under the command of Oblt.z.S. Hans Hellmann. On 5 May 1945, U-733 transferred to Flensburg, were the U-boat was attacked by US aircraft and scuttled after receiving heavy damage.