German Submarine Warfare 1914-1918 in the Eyes - British Naval ...

oats out daily on merchant war cruises. The number of deployable ocean-going
boats was low, reflecting their modest fifteen percent average usage in the
merchant war.
In 1916, the number of available ocean-going boats in the North Sea and
Atlantic had more than doubled, but relative usage in the merchant war was less
than in the year prior (13%). Most available submarines were used for military
purposes, like scouting enterprises against the Grand Fleet in the North Sea. Until
the summer of 1917 a small number of ocean-going submarines were on patrol in
the Baltic and the Black Sea, operating against the Russian Fleet. 1917 and 1918 are
the pivotal years of the submarine merchant war in the North Sea and Atlantic,
when a high number of ocean-going boats were made available and their percentile
usage had more than doubled to 33% and 36% respectively.
Table 10: Ocean-going U-boats available 1915-1918 43
OceangoingUboats
avail. per
day
North Sea + Atlantic Mediterranean
Used on
military
patrols per
day
Used on
merchant
war per
day
Avail. Uboats
used on
merchant
war
OceangoingUboats
avail. per
43 Numbers based on: NA, HW 7/3; on: Spindler, Handelskrieg; on: Bendler, UB- und UC-Boote.
xxiv
day
Used on
military
patrols per
day
Used on
merchant
war per
day
Avail. Uboats
used
on
merchant
war
1915 15 1 2 15% 2 1 37%
1916 39 6 5 13% 12 1 4 31%
1917 86 3 29 33% 30 10 32%
1918 82 1 29 36% 32 1 9 29%
The Mediterranean saw a steady upward tick of available boats along with a
commensurate increase in targeting merchant traffic. From 1916 onwards more
than a quarter of the German ocean-going submarine force was stationed in the
Mediterranean Sea.
German Submarine Warfare 1915
The daily average of submarines on merchant war cruise in the North Sea and
Atlantic for 1915 is a modest spread of zero to six boats. In fact, it appears that the
merchant war was suspended for a period of several months. During the first
unrestricted submarine warfare period in 1915, March to September, there were
never more than half a dozen boats at sea at any one time. When the eight- to ten-
day transit time to and from North Sea bases is taken into account, during a routine
patrol of about five weeks there were never more than four boats operating in the
Atlantic. The hunting was meagre. Practically the only exceptions were the sinking
of the passenger liners Lusitania in May and Arabic in September. Pyrrhic victories,
both. They brought Germany instant, sharp censure from President Wilson and
catastrophic loss of American public support. Unrestricted warfare was suspended
at once and stopped altogether in September. The sinkings had done incalculable