This episode is dedicated to the sea and its stories. We will present the largest and most majestic ships ever built. We will tell the adventures of men and sailors who challenged the unknown on the water. From the ships of the first Polynesian migrants to the fast Phoenician boats. We will reveal who pirates, corsairs and freebooters were, legendary protagonists of the oceans for almost three centuries. Alberto Angela tells us the little-known story of the Graffspee, a powerful German battleship in the South Seas of the world. Man overboard! One of the most common and dangerous accidents that can happen to sailors. How can we save ourselves? The emotional story of a survivor. We also analyze the causes of the most famous sea tragedy in history: the sinking of the Titanic. Thanks to the collaboration of the Italian Navy we participated in the rescue exercises of a submarine in difficulty.