Günter Hessler joined the Reichsmarine of the Weimar Republic on 5 April 1927 as a member of "Crew 1927" (the incoming class of 1927).

He underwent basic military training in the 8th company, 2nd department of the standing ship division of the Baltic Sea in Stralsund (5 April 1927 – 3 July 1927).

[1] On 2 October 1936 he was appointed watch officer on the Aviso Grille, Adolf Hitler's state yacht, and on 30 March 1938 transferred to the battleship Gneisenau.

On the outbreak of World War II Falke was tasked with laying defensive naval mines and escort and security duties in the North Sea.

[3] After the war Hessler spent over a year in Allied captivity, and testified at the Nuremberg Trials on behalf of the Ubootwaffe and his father-in-law, Großadmiral Karl Dönitz.