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.

BoatShips sunkTons sunkShips hit during
U 35226 ships538,500 tons1915 - 1918
U 39154 ships406,325 tons1915 - 1918
U 38139 ships293,134 tons1915 - 1918
U 34119 ships257,652 tons1915 - 1918
U 5388 ships225,364 tons1916 - 1918

See 20 most successful U-boats of WWI.

Some statistics:

U-boats during WWI: 375
U-boats during WWII: 1156