Allied Warships
Check out our new extensive section on all the Allied Warships during WWII in all theatres of the war.Over 21,000 ships
The U-boats of World War One
1914-1918
Just like in WWII Germany deployed a large U-boat force against the western powers. But the main difference during the two wars was that in World War One the Germany Navy had a very large surface (battleships, destroyers, cruisers) fleet while in WWII the U-boats had to shoulder the fight pretty much alone.
List of all WWI U-boats
We list them as U, UB and UC classes.
U-boat types
See the 33 types of U-boats used in the war.
U-boat finder
Look for any commissioned WWI U-boat
(including Austrian-Hungarian)
During 1914-1918 375 U-boats sank about 7,672 merchant ships (15,716,793 tons).
5 most successful U-boats
The following are the most successful U-boats during WWI, in terms of ships sunk.
| Boat | Ships sunk | Tons sunk | Ships hit during |
| U 35 | 226 ships | 538,500 tons | 1915 - 1918 |
| U 39 | 154 ships | 406,325 tons | 1915 - 1918 |
| U 38 | 139 ships | 293,134 tons | 1915 - 1918 |
| U 34 | 119 ships | 257,652 tons | 1915 - 1918 |
| U 53 | 88 ships | 225,364 tons | 1916 - 1918 |
See 20 most successful U-boats of WWI.
Some statistics:
U-boats during WWI: 375U-boats during WWII: 1156