It’s a little recognised fact that U-boats of the Kaiserliche Marine (the Imperial German Navy) sank far more vessels in the First World War than U-boats of the Kriegsmarine did in the Second World War. Exact figures are difficult to come by, but a number of records put together after the war, and more recently, show the extent of the difference.
In The U-boat War 1914-1918, Edwyn Gray claims that “according to the most reliable statistics available, a world total of 5,708 ships were destroyed by the U-boats, representing the almost incredible total of 11,018,865 tons capacity.”
This figure has most likely come from the British statistics published after the war and in The U-boat Offensive 1914-19145, V.E. Tarrant includes quite detailed statistics on merchant ship losses to U-boats that match it quite closely. He also observes that research suggests the German totals tend to be more accurate and include losses to mines laid by U-boats. The figures provided for 1917 may therefore be considerably higher than the British total.
Year German Figures British Figures
1914: 3 (2,950) 3 (2,950)
1915: 636 (1,191,704) 468 (1,176,829)
1916: 1,309 (2,186,462) 1,125 (2,108,530)
1917: Unknown (6,149,070) 2,609 (6,026,128)
1918: 1,305 (2,754,152) 1,077 (2,649,748)
Fishing Vessels: Already included 614 (62,139)
Total: 5,862 (12,284,757) 5,896 (12,026,324)
(Using British figure for 1917)
Business in Great Waters: The U-boat Wars 1916-1945 by John Terraine, includes the following totals in Appendix C: 12,850,814 tonnes of worldwide shipping sunk by U-boats between 1914-1918, of which approx 7,759,090 was British Merchant shipping. Sourced from CE Fayle, Seaborne Trade (1924).
More recent research has been conducted by project volunteers Peter Crick and Richard Wyatt, who have checked the losses attributed to U-boats on the comprehensive website U-boat.net. These totals include attacks, damaged vessels, captures and sinkings caused by all forms (scuttling, deck gun, torpedoes and mines) and include U-boats of the German Navy and the Austro-Hungarian Navy. The losses also include warships, something that post war totals tended to ignore.
The totals came to:
7655 total attacks carried out by U-boats.
691 (2,742,917 tonnes) ships damaged.
115 ships captured and taken as prize
6849 ships sunk
So the post war statistics reach as high as 5,800 (mostly merchant) ships sunk by U-boats, whilst more modern research suggests that possibly 1,000 more ships of all types were lost to U-boats. By comparison, the most reliable statistics for the Second World War suggest that only approximately 3,500 attacks were made on ships by U-boats, resulting in approximately 3,100 ship losses. In Business in Great Waters: The U-boat Wars 1916-1945, John Terraine identifies 5,140 ship losses to all causes in the Second World War, substantially less than the total number just to U-boats in the First World War.
Written and researched by Stephen Fisher (MAT HLF Forgotten Wrecks Research Officer).
With help from volunteers Peter Crick and Richard Wyatt.