At the start of the First World War Kophamel was a Kapitänleutnant and commanded . In October 1915 he was promoted to Korvettenkapitän and in December of that year took command of the  Pola Flotilla. In July 1917 he returned to sea, in command of U-151 and later .
At the beginning of World War I, Kophamel was a Kapitänleutnant and led . In October 1915, he was upgraded to Korvettenkapitän and in December of that year took charge of the Pola Flotilla. In July 1917, he returned to sea, commanding U-151 and subsequently .