thumb|Type VIIC U-boat
List of successful U-boats contains lists of the most successful German U-boats in the two World Wars based on total tonnage.
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.
{| class="wikitable sortable"
|+ 5 Top-scoring U-boats of World War I
|-
! Boat
! Type
! Commissioned
! Total<br/>tonnage
! Ships<br/>sunk
! Patrols
! class="unsortable" | Fate
! class="unsortable" | Captains
|-valign="top"
|
| Type U 31
| 3 November 1914
| align=center | 505,121
| align=center | 220
| align=center | 17
| Surrendered, 26 November 1918
| Waldemar Kophamel<br/>Lothar von Arnauld de la Perière<br/>Ernst von Voigt<br/>Heino von Heimburg
|-valign="top"
|
| Type U 31
| 13 January 1915
| align=center | 404,774
| align=center | 149
| align=center | 19
| Surrendered, 22 March 1919
| Hans Kratzsch<br>Walter Forstmann<br>Heinrich Metzger
|-valign="top"
|
| Type U 31
| 15 December 1914
| align=center | 287,811
| align=center | 134
| align=center | 17
| Surrendered, 23 February 1919
| Max Valentiner<br/>Wilhelm Canaris<br/>Hans Heinrich Wurmbach<br/>Clemens Wickel
|-valign="top"
|
| Type U 31
| 5 October 1914
| align=center | 257,652
| align=center | 119
| align=center | 17
| Missing, 9 November 1918
| Claus Rücker<br/>Wilhelm Canaris<br/>Johannes Klasing
|-valign="top"
|
| Type U 51
| 22 April 1916
| align=center | 224,314
| align=center | 87
| align=center | 13
| Surrendered, 1 December 1918
| Hans Rose<br/>Otto von Schrader
|}
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.
{| class="wikitable sortable"
|+ 10 Top-scoring U-boats of World War II
|-
! Boat
! Type
! Commissioned
! Total<br/>tonnage
! Ships<br/>sunk
! Patrols
! Fate
! Captains
|-
|
| VIIB
| 22 April 1939
| 300,537
| 51
| 12
| Scuttled, 3 May 1945
| Herbert Schultze<br/>Hans-Rudolf Rösing<br/>Heinrich Bleichrodt
|-
|
| VIIB
| 18 April 1940
| 244,658
| 38
| 8
| Scuttled, 17 March 1941 after depth charging by .
| Otto Kretschmer
|-
|
| IXB
| 18 April 1940
| 237,596
| 45
| 11
| Decommissioned March 1944. Sunk by bombs in Kiel, 15 April 1945.
| Viktor Schütze<br/>Werner Winter
|-
|
| IXB
| 11 June 1940
| 225,637
| 48
| 11
| Lost with all hands, 2 April 1943 after depth charging by and .
| Georg-Wilhelm Schulz<br/>Johann Mohr
|-
|
| IXB
| 30 May 1940
| 222,705
| 44
| 12
| Decommissioned 17 June 1944. Scuttled in port, 19 August 1944. Refloated and taken into French service as Blaison.
| Karl-Heinz Moehle<br/>Reinhard Hardegen<br/>Horst von Schroeter
|-
|
| IXB
| 8 October 1940
| 217,786
| 39
| 13
| Lost with all hands 18 August 1944 after depth charging by a Sunderland of 201 Squadron RAF.
| Günter Hessler<br/>Harald Gelhaus<br/>Volker Simmermacher<br/>Karl-Heinz Fritz
|-
|
| IX
| 4 August 1938
| 202,467
| 55
| 11
| Scuttled, 8 May 1945
| Heinrich Schuch<br/>Werner Hartmann<br/>Victor Oehrn<br/>Asmus Nicolai Clausen<br/>Ulrich Folkers
|-
|
| IXC
| 20 March 1940
| 200,021
| 33
| 9
| Sunk 6 May 1944 by Grumman F4F Wildcats and Grumman TBF Avengers of , rammed by destroyer escort .
| Richard Zapp<br/>Friedrich Markworth<br/>Paul Frerks<br/>Gerhard Seehausen
|-
|
| IXC
| 11 February 1941
| 197,998
| 33
| 10
| Sunk 10 April 1944, depth charges and rockets fired by F4F Wildcats and TBM Avengers of .
| Karl-Friedrich Merten<br/>Albert Lauzemis<br/>Ekkehard Scherraus<br/>Gerhard Seehausen<br/>Albert Lauzemis
|-
|
| 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.<br>
Reason behind her sinking is still unknown with theories ranging from attacks by corvettes and , mines, mechanical failure, and possibly becoming victim of her own torpedoes.
| 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.