[ Autographs ] GUNTHER PRIEN (1908 - 1941) Germany's first U-boat acewho sneaked his U-47 into the British anchorage at Scapa Flow and sank the Royal Oak with a huge loss of life. He went on to sink a total of 28 merchant ships before meeting his own end in a depth charge attack. Excessively rare and most desirable S.P. 3.5in x 5.5in b/w, a three-quarter length frontal portrait showing Prien in uniform with Iron Cross, smiling broadly. A Hoffman image, signed in full nearbottom with contrast just fair.