Which academic subjects did Columbus study?

Christopher Columbus had little in the way of formal education. From his teenage years onward, he spent most of his time out at sea, which would become his natural habitat. At first, Columbus traversed the Mediterranean on numerous voyages for merchants. But later on, he would take on more challenging journeys, heading out west into the Atlantic Ocean.
Though seamanship was largely a practical business, it was still important to have some understanding of academic subjects such as math, cartography (map-making), navigation, and astronomy. Columbus combined his studies of these subjects with the day-to-day duties of a sailor. After once being shipwrecked off the coast of Portugal, Columbus began to study in earnest, hoping to avoid such similar disasters at sea in the future. Despite all his hard work, however, Columbus's most famous achievement—the "discovery" of America—came about as a result of a monumental blunder in navigation. Columbus had originally hoped to establish a direct sea route from Western Europe to Asia. But, due largely to his underestimating the circumference of the globe, he ended up stumbling across America instead.