A month after the outbreak of World War I, in August 1914, the submarine broke into the headlines as a spectacular, if not dynamic, naval weapon. First successes were against warships; one German and three British cruisers were early victims. The Germans, however, soon discovered other tasks for which the U-Boats appeared eminently suited. Experiments with U-Boats against merchantmen during the first six months of the war brought recognition of the submarine’s capabilities as a commerce destroyer using torpedoes, medium-caliber guns, and mines as her weapons.
In the wars against commerce from 1914 to 1918 and from 1939 to 1945, German submarines set records that no other submarine arm has approached. Operating roughly half of the submarines in the world in both wars (373 in World War I and 1,170 in World War II), the German submarine force sank more than 6,000 enemy and neutral merchant vessels in World War I and 2,779 in World War II. (The Germans counted only ships over 500 gross tons in World War II.) The Germans sank more than 26 million gross tons of shipping in both wars, the World War II U-Boat effort accounting for 14 million tons of that total. Results of other nations’ efforts in submarine commerce warfare are negligible, save for the American submarine campaign in World War II against the Japanese merchant fleet. In that conflict, American boats sank 1,113 ships totalling 5,320,094 gross tons.
An important point to consider here is the abundance of targets furnished German U-Boat skippers compared to those of the other major submarine powers. Though Germany possessed the second largest merchant marine in the world in 1914, the Allies did not have to undertake submarine warfare against it. A distant naval blockade, made possible by Germany’s unfavorable geographical position for ocean commerce in time of war, effectively throttled the German merchant fleet from the beginning of the war, save in the Baltic. World War II produced a similar blockade and the same result.
The record for the most tonnage sunk by one submarine and by one commanding officer belongs almost entirely and understandably so, to the Germans. Above the arbitrary 100,000 gross tons cut-off, a figure roughly indicating 20 ships sunk, German boats hold the first 34 places for World War I. U-35 still holds the record for both wars with 224 ships, totalling 539,711 gross tons. Three boats were over the 300,000-ton mark, and three more were over the 200,000-ton mark.
As for individual commanders, 25 U-Boat commanders broke into the 100,000-ton category during World War I, 18 of them while in command of a single boat. The top three individual tonnage aces of World War I commanded the three most successful boats; Kapitanleutnant Lothar von Arnauld de la Periere, whose record of 194 ships, 457,606 tons, has never been equaled, commanded U-35; Kapitanleutnant Dr. Walther Forstmann was second in U-39 and Kapitanleutnant Max Valentiner was third in U-38.
Of the non-German submarines and submariners of that war, certainly the Austrian boats U-5 and U-14, and their captain, Leutnant Baron von Trapp, and the British submarines HMS E-9 under Lieutenant Commander (later Admiral Sir) Max Horton and HMS E-11 under Commander Nasmith deserve mention.
World War II produced a similar pattern of achievement, though one should remember that the number of boats in action in World War I quadrupled in this war. Of the 38 submarines of the combatant powers that sank over 100,000 tons of merchant tonnage, 35 were German, one was Italian, and the other two were Russian. Of the German group, U-48 alone reached the 300,000-ton class to join U-38 and U-39 of World War I in that select circle. As one would expect, German commanders dominated the individual merchant tonnage list, taking the first 41 places. It is interesting to note that German listings always delineate between merchant and naval sinkings, perhaps because of associating their U-Boat offensives entirely with the concept of the handelskrieg-commerce warfare. On the other hand, most naval powers simply add the tonnages of the two categories together.
There was another side to submarine operations in both World Wars. All the major combatants pitted their submarines against fleet units, including other submarines, at one time or another. In World War I, German submarines set the record by sinking 94 naval vessels, including ten battleships, 18 cruisers, 21 destroyers, and 13 submarines (including four of their own).
That record was broken by American submarines in World War II when they sank 201 naval ships, including a battleship, nine carriers, 15 cruisers, 22 submarines and 46 destroyers. The U. S. Navy’s submarines accounted for over one-quarter of the Japanese fleet.
The Germans were second with 148 naval sinkings by U-Boats that included two battleships, six carriers, six cruisers, 52 destroyers, and nine enemy submarines plus a few of their own.
The all-time submarine ace against naval ships is Kapitanleutnant Otto Hersing, who sank two battleships and two cruisers between 1914 and 1916.
These were the World War boats and the captains who set the records. A chance to best these records may never return.