Albrecht Brandi Albrecht Brandi ( June 20 , 1914 – January 6 , 1966 ) was a German U - boat commander in World War II . Together with Wolfgang Lüth he was the only Kriegsmarine sailor who was awarded with the Knight ' s cross with Oak Leaves , Swords , and Diamonds . Brandi was well known as a daring and aggressive U - boat commander . During his naval career Brandi destroyed twelve ships , including one minelayer and two destroyers . With these victories Brandi became the U - boat commander who destroyed the most warship s . However , he is not the U - boat commander with the most ships sunk ; that record is held by Otto Kretschmer with 47 victories . Brandi is ranked number 24 on the top scoring list of Germany ' s U - boat commanders . Biography . Early years . Brandi joined the Nazi Germany ' s " Kriegsmarine " in 1935 and studied to become a naval officer on board on the . After graduating he became commander of the minesweeper " M - 1 " . During the first year of World War II , Brandi cleared various minefields in the North Sea . In April 1941 Brandi started his U - boat training at the U - boat training camp in Neustadt in Holstein . From May 1941 to April 1942 , Brandi was a " Kommandantenschüler " ( Commander - in - training ) aboard , which was commanded by the famous commander Erich Topp , for three patrols . On 9 April 1942 Brandi was given the command of his own U - boat , and completed the usual training with the new boat in the 5th U - boat Flotilla . War in the Mediterranean Sea . For his first patrol , Brandi left Kiel in August 1942 , operating in the Western Approaches before arriving at St . Nazaire in October . During this time Brandi destroyed four merchant ships . On his second patrol , in November 1942 , Brandi was ordered to the Mediterranean Sea . To get to his destination Brandi had to traverse the heavily guarded Strait of Gibraltar . He decided to proceed through the Strait on the surface by night with engines stopped , relying on the current in the Straits ( which on the surface move from the Atlantic into the Mediterranean ) to propel his boat through . During this extremely dangerous trip , Brandi was discovered by a Short Sunderland bomber which dropped two depth charge s . The bombs missed the U - boat and Brandi succeeded in making the breakthrough . During this patrol Brandi claimed to have sunk one destroyer and damaged a tanker , though neither were confirmed by Allied records . In the Mediterranean , " U - 617 " was assigned to " 29th U - boat Flotilla " , located in La Spezia and Toulon and commanded by Fritz Frauenheim . Through 1943 Brandi made various patrols in the Mediterranean Sea . During these patrols Brandi targeted British warships that were attacking the German and Italian supply ships that were so vital for the Afrikakorps in North Africa . The Mediterranean Sea offered particular challenges for a U - boat captain . The often shallow waters offered little chance to dive deep and the British had air cover over the entire southern half of the Mediterranean . This , coupled with the fact that his opponents were warships or heavily guarded convoys , makes Brandi ' s achievements remarkable . On his third patrol , in December 1942 , Brandi sank the ocean tug " St Issey " , and two more merchant ships . In February 1943 Brandi sank the British minelayer a few miles from the Maltese coast . The destruction of this ship was important , as the minelayer had been an integral part of the defense of Malta . Brandi was awarded the Knight ' s Cross of the Iron Cross for this victory . He also sank two ships from a well - protected convoy . In April 1943 , Brandi claimed the sinking of a light cruiser , 40 miles off Gibraltar . Brandi was awarded Oak Leaves with his Knight ' s Cross , though this sinking was also not confirmed . Two more patrols followed in June and July , though these had no success . In September 1943 , in his last patrol in " U - 617 " , Brandi sank , a Hunt class destroyer , off Gibraltar . A few days later , on 12 September , she was attacked near the Moroccan coast by British Wellington aircraft . One aircraft was claimed by the German Flak crew , though this is unconfirmed , while depth charge s exploded close to the " U - 617 " . The resultant damage was so severe that Brandi decided to abandon ship off Melilla , Spanish Morocco . After evacuating into rubber boats , the crew managed to reach the shore without loss and were interned by Spanish troops . Brandi was loosely confined in the officers ' camp near Cadiz , and from there he succeeded in returning to Germany . The wrecked " U - 617 " , aground offshore , was finally destroyed and sunk by air attack and naval gunfire . In January 1944 Brandi returned to Toulon and took command of . Brandi completed one patrol with " U - 380 " , but the boat was destroyed on 13 March 1944 in Toulon by a bombing raid of the 9th USAAF . In April 1944 Brandi became commander of . During his first patrol with her in May 1944 Brandi sank the destroyer . Following this he received the Swords to his Knights Cross with Oak Leaves . Brandi as a leader . During the next patrol with " U - 967 " in June 1944 , Brandi became seriously ill and had to return to base . Brandi then was appointed commander of all U - boats in the Eastern Baltic Sea . Under his command many ships were destroyed in the Baltic Sea , and Brandi was awarded with Diamonds to his Knight ' s Cross for his leadership of the U - boat fleet . In the last year of the war , Brandi became chief commander of the mini submarine fleet . After the war Brandi started a career as an architect . Achievements . During his U - boat service Brandi claimed , and was credited with , sinking 26 ships , of . This claim included ten warships ; two cruisers and eight destroyers . Although ships sunk in the Mediterranean were doubled for award purposes , and extra credit was given for sinking warships , Brandi ' s actual sinkings were " startlingly less " according to Blair . The confirmed total was :