Hitler's plans to invade Norway and Denmark in the spring of 1940 led to the withdrawal of the fleet's surface warships and most of the ocean-going U-boats for fleet operations in Operation Weserübung.
Hertil kom, at Hitlers plan om at invadere Norge og Danmark i foråret 1940 medførte tilbagetrækning af flådens slagskibe og de fleste af de oceangående ubåde for at forberede flådeoperationerne i Operation Weserübung.