‘Planet Earth’ is a strange name since two thirds of its surface is covered by water, here, from a geographical point of view, ‘Planet Ocean’ would be more appropriate. However, the physical composition of the Earth has implications that are much more interesting for history than its name. Human expansion and the conquest of the world, an encounter with distant cultures, the creation of great commercial systems, and the consolidation of a global empire, only became possible because of one of the most surprising human achievements: dominion over the sea.

The final book of Gonzalo Fernández de Oviedo's Historia General y Natural de las Indias is devoted to the misfortunes of sailing, and he introduces the subject with an interesting reflection on the importance of navigation in the history of mankind. Quoting Pliny, who wrote about sails made of linen or canvas in book nineteen of his Natural History, he remarks: ‘what greater miracle can there be than to have a plant which thus makes Egypt a neighbor of Italy’. For Oviedo, on the other hand, it was not until the 16th century that the real power of using sails was really appreciated. While Pliny thought that linking Italy with Egypt was one of the great technical achievements of humanity, Fernández de Oviedo believed that it could not be compared with the new maritime routs of the 16th century: