ABSTRACT
The use of risk was connected with navigation from the beginning. The Arabs navigated the deserts and after the Islamic expansion, the Indian and Mediterranean seas. This chapter shows how the opening of the Atlantic Ocean was carried out by Portuguese and Castilian seamen in their voyages around Africa, India and the Americas. What kind of theological, cosmographic and geographical knowledge made possible this adventure? How did the art of navigation enabled people like Columbus to navigate the open sea?
