Navis Neptun 1/1250 72AN U35, a German U31-class submarine, 1915

U35 was the most successful U-boat ever! She sank 225 ships of 535900 GRT. She undertook 25 patrols under 4 commanders ranging as far as the Mediterranean & off the West African coast, surviving the war to be broken up in 1919-20. The most successful WW2 boat was U48, sinking 51 ships. There were 11 boats of the U31-class, U31-41.