The 'raw' potato that Larsen crushes within his fist was actually lightly precooked, but it became Raimund Harmstorf's signature scene as much as the role of Wolf Larsen, the notorious 'Seewolf' became the role he was constantly being recognized for.
Much to his dissatisfaction, Harmstorf's voice was being dubbed by the older dubbing actor Kurt E. Ludwig in order to add further authenticity to his villain character. Another well-known character dubbed by Ludwig was Scotty from Star Trek.
Principal filming was mostly done in Romania. Locations included the Black Sea, the harbor towns of Constantza and Braila, and the villages Snagov and Buftea.