Captained by one of the Kaiser's most successful submarine commanders, U-35 prowled the sea, especially the Mediterranean, during World War I. That was the war in which submarines first proved their mettle and their promise and Germany and, to a lesser extent its Austrian ally, led the world in advanced U-boat design and tactical deployment.
Field as opposed to studio photography was in its relative infancy during the Great War and while there are a fair number of films of army activities, including some combat footage, there's very little of the critical war at sea.
It's not clear who got the idea of filming U-35's combat patrol but after the war it was released with a pious notice announcing the film was meant to show the horrors of war.
Actually there are no horrors here. All the footage was shot while the warship was surfaced and there are no interior scenes. Much of the film shows the sub taking allied merchantmen captive and, in most cases, sinking the vessels by charges placed by a boarding party supplemented with torpedoes and deck gun fire. No one dies in this documentary.
While the signboards announce that some of the vessels were captured after fierce resistance, this is almost certainly false information. A submarine can not afford to incur any damage that might compromise its submersibility making it vulnerable to surface combatants and, even in World War I, aircraft. The roster of sunken merchantmen reflects easy pickings for a U-boat in the days when the Germans had no fear of aerial assault or of being tracked down by the deadly hunter-killer task groups of the next war.
The U-boat crew is shown swimming and gamboling around the narrow deck. The skipper appears confident and proud as well he ought to have been.
The restored print, available on a DVD with other WWI films ("World War I Films of the Silent Era") is quite good.
"The Log of the U-35" is a treat for all students of naval warfare. And a very rare one at that.
10/10 (for its historical and archival value)