U-boats in World War I
I’ve been interested in submarine warfare 0f the Second World War since I was in middle school. There are a lot of books written in English about the German U-boat campaign targeting Allied ships in the Atlantic and also the American submarine war against Japanese merchant shipping in the Pacific. Relatively little has been written in recent times, though, about submarine operations of any nation during the First World War.
That’s why I was happy to discover a copy of Edwyn Gray’s book, The U-boat War: 1914-1918 (which was originally published in the 1970s as The Killing Time) in Manhattan’s mecca for rare books: the Strand Book Store. I’m really glad I bought this book, because after reading it, I disabused myself of several erroneous notions about these early German submarine operations.
For example, I previously believed that German submarines during WWI in comparison to their counterparts in WWII
- were generally smaller, slower, and carried less fuel, crew, and torpedoes,
- exclusively operated in the coastal waters of Western Europe, and
- did not wage as large or effective of a campaign against merchant shipping.
All of these preconceptions turned out to be false. By way of comparing the U-boat campaigns of the First and Second World War, I turned to some data from uboat.net, an ongoing research project by an amateur historian which I’ve enjoyed visiting since I first started using the internet in the mid-1990s.
Just looking at how many ships U-boats attacked during each war, it’s evident that the number of ships hit by submarines in the 1910s surpasses the totals of the 1940s:

Source: Uboat.net
The chart on the right-hand side also shows that submarine effectiveness from 1943 onward took a big dive, so to speak. From that year on, the Allied countermeasures against U-boats became so effective that the German submarines really became the prey rather than the hunters. U-boat losses also increased dramatically after 1943, a trend also seen during WWI but not on such a stark scale:

Source: Uboat.net
By observing the graphs above, it would seem that the submarine campaign against the Allies was way more effective in the First World War than in the Second, especially since the German Navy only commissioned a smaller force of 375 boats during the first war compared to the 1,154 submarines of the second war. But we have to consider other information.
The U-boats of WWII seem to have hunted after larger game than their forefathers. For example, it wasn’t below a U-boat captain in WWI to sink fishing boats or sailing vessels with his deck gun, but by WWII those weren’t considered worthwhile targets. The ships hit graphs above include all types of ships — large and small. The German submarines of WWII, though, sank more total tonnage than their predecessors (12.8 million in WWI compared to 14.0 million in WWII).
And U-boats during World War I did sail far beyond the coastal water of Western Europe. They participated in operations in the Mediterranean Sea and even reached the east coast of America to sink Allied ships within sight of New York City. The WWII equivalent of this campaign is famously documented in Michael Gannon’s excellent book, Operation Drumbeat, but there is no recent account about the submarine campaign off of American shores during the First World War.
As for the boats themselves, the U-boats in the earlier war were much more similar to their counterparts in the later war than I had previously thought. The table below compares the technical specifications of several representative boats from WWI (in blue) and WWII (in green):

Source: Uboat.net
The only glaring difference between the boats of WWI and WWII is the maximum diving depth (which by the 1940s was up to four times deeper for many boats than in WWI). Another key difference may be diving time — WWI boats may have taken longer to plunge beneath the waves in cases of Allied detection — but I don’t have data for that. But the U-boats of WWI were very comparable in size, speed, range, and armament to their later cousins.
Regardless of the various measures of success, I think that the U-boat campaigns during the First World War are an undervalued area for research and writing. The standard narratives about this time period tend to fixate on the atrocities perpetrated by a handful of unscrupulous U-boat captains, such as the sinking of the Lusitania. Edwyn Gray’s account is full of interesting anecdotal stories of U-boat captains and their crews that oftentimes went out of their way to guarantee the safety of their victims while also sinking a ton of enemy ships. The most successful U-boat captain during the First World War — Lothar von Arnauld de la Perière, who sank almost 200 ships for a total of over 455,000 tons — is a case in point.
So if you’re a fan of reading about submarine warfare and have not read much about German U-boat operations during WWI, it’s definitely worth exploring further. And Edwyn Gray’s work is an entertaining and edifying introduction to that topic.
[…] Unrestricted submarine warfare had a 0% chance of breaking the British blockade unless it was unleashed against the cruisers enforcing the quarantine. The German failure to even try to engage in blockade running (let alone directly attack the British blockaders) petty much doomed the Kaiserliche Marine to irrelevance throughout the war; though modern historians too often miss the fact that commerce raiding is considerably less effective than smuggling when it comes to blockade busting. A century on, the 5,000 Allied vessels that First World War German submarines sent to the bottom is held up as a remarkable achievement… […]