Submarines were the single greatest cause of vessel sinkings during the Second World War – about 34% of the total 20,000 ships that were sunk. The Germans in their U-boats accounted for 2,955 of these vessels and collectively they totaled over 14 million tons of shipping. Less well known is the US submarine war against the Japanese. American submarines accounted for 1,994 vessels with a tonnage of 5.6 million. Further down the list was the UK who accounted for 1,625 vessel sinkings of 1.5 million tons. The Japanese, surprisingly, accounted for only 187 vessel sinkings of less than a million tons.
It is worth noting a couple of things about these numbers:
- Not all ships listed in the database have a tonnage value. Records for the western Allies tend to be better and more complete and these were often the victims of German submarine attacks. Japanese records – the target of US and UK submarines in many cases – are less complete.
- Many of the vessels sunk by US submarines were small vessels (less than 20 tons) including fishing vessels and small junks in use by the local population (See the records for USS Blenny, for instance).
Sunken Ships of the Second World War 