List of most successful German U-boats

List of successful U-boats contains lists of the most successful German U-boats in the two World Wars based on total tonnage.^{[clarification needed]}

World War I

This list contains the 5 most successful German U-boats during the First World War based on total tonnage. Only sunk commercial vessels are included, not military (warships) nor damaged ships.

5 Top-scoring U-boats of World War I
Boat	Type	Commissioned	Total tonnage	Ships sunk	Patrols	Fate	Captains
SM U-35	Type U 31	3 November 1914	539,741	224	17	Surrendered, 26 November 1918	Waldemar Kophamel Lothar von Arnauld de la Perière Ernst von Voigt Heino von Heimburg
SM U-39	Type U 31	13 January 1915	404,478	154	19	Surrendered, 22 March 1919	Hans Kratzsch Walter Forstmann Heinrich Metzger
SM U-38	Type U 31	15 December 1914	299,985	137	17	Surrendered, 23 February 1919	Max Valentiner Wilhelm Canaris Hans Heinrich Wurmbach Clemens Wickel
SM U-34	Type U 31	5 October 1914	262,886	121	17	Missing, 9 November 1918	Claus Rücker Wilhelm Canaris Johannes Klasing
SM U-33	Type U 31	27 September 1914	229,598	84	16	Surrendered, 16 January 1919	Konrad Gansser Gustav Sieß Hellmuth von Doemming

World War II

This list contains the 10 most successful German U-boats during the Second World War based on total tonnage. Both commercial and military vessels (warships) are included but only sunk ships are included, not damaged ships.

10 Top-scoring U-boats of World War II
Boat	Type	Commissioned	Total tonnage	Ships sunk	Patrols	Fate	Captains
U-48	VIIB	22 April 1939	307,935	52	12	Scuttled, 3 May 1945	Herbert Schultze Hans-Rudolf Rösing Heinrich Bleichrodt
U-99	VIIB	18 April 1940	244,658	38	8	Scuttled, 17 March 1941 after depth charging by HMS Walker.	Otto Kretschmer
U-103	IXB	18 April 1940	237,596	45	11	Decommissioned March 1944. Sunk by bombs in Kiel, 15 April 1945.	Viktor Schütze Werner Winter
U-124	IXB	11 June 1940	224,953	48	11	Lost with all hands, 2 April 1943 after depth charging by HMS Stonecrop and HMS Black Swan.	Georg-Wilhelm Schulz Johann Mohr
U-123	IXB	30 May 1940	223,816	44	12	Decommissioned June 1944. Scuttled in port, 19 August 1944. Refloated and taken into French service as Blaison.	Karl-Heinz Moehle Reinhard Hardegen Horst von Schroeter
U-107	IXB	8 October 1940	217,786	39	14	Lost with all hands 18 August 1944 after depth charging by a Sunderland of 201 Squadron RAF.	Günter Hessler Harald Gelhaus Volker Simmermacher Karl-Heinz Fritz
U-37	IX	4 August 1938	202,528	55	11	Scuttled, 8 May 1945	Heinrich Schuch Werner Hartmann Victor Oehrn Asmus Nicolai Clausen Ulrich Folkers
U-66	IXC	20 March 1940	200,021	33	12	Sunk 6 May 1944 by Grumman F4F Wildcats and Grumman TBF Avengers of USS Block Island, rammed by destroyer escort USS Buckley.	Richard Zapp Friedrich Markworth Paul Frerks Gerhard Seehausen
U-68	IXC	11 February 1941	197,998	33	10	Sunk 10 April 1944, depth charges and rockets fired by F4F Wildcats and TBM Avengers of USS Guadalcanal.	Karl-Friedrich Merten Albert Lauzemis Ekkehard Scherraus Gerhard Seehausen Albert Lauzemis
U-47	VIIB	17 December 1938	191,919	31	10	Missing with all hands, on or about 7 March 1941 while patrolling south of Iceland between 59 deg and 62 deg north. Possibly depth-charged by destroyers HMS Wolverine and HMS Verity after being located using Type 286 ASDIC newly fitted to both destroyers.	Günther Prien

References

uboat.net webpage about the most successful U-Boats of World War I - This list does not include military vessels.
uboat.net webpage about the most successful U-Boats of World War II - This list does not include military vessels and is therefore not identical to list above.
uboataces.com webpages about the most successful U-Boats of World War II - This list seems to miss U-123 in top 5 list.