Erhard Maertens or Eberhard Maertens (26 February 1891 – 5 May 1945) was a German Vizeadmiral of the Kriegsmarine during World War II. From 16 June 1941 to 5 May 1943, he was Chief of Office of Naval Intelligence, Naval War Command (German: Marinekommandoamt) in the Oberkommando der Marine. Maertens was known for underestimating British intelligence, and specifically, overrating the security of the Naval Enigma cipher machine. In 1941, he held a naval enquiry into the strength of Naval Enigma security after the capture of U-boat U-570, and attributed all the suspicious losses in U-boats at the time to the British Huff-Duff. In the second enquiry, ordered by the Commander-in-Chief of the Navy (German: Oberbefehlshaber der Kriegsmarine) Karl Dönitz, in May 1943, he investigated a number of a