Professor Calculus's Shark Submarine

In shark-infested waters, Tin Tin and Snowy search for treasure disguised in Professor Calculus's shark submarine. Their mission is threatened when the sub gets entangled in seaweed! Hergé is said to have gotten the idea for the sub from a photo of German war machinery. From The Adventures of Tin Tin: Red Rackham's Treasure, 1943.