Exploration
In the Pacific Ocean, Jorge de Menezes (c. 1498–?), discovered Papua New Guinea. García Jofre de Loaísa (1490–1526), discovered the Marshall Islands. Explorations of the Americas began with the initial discovery of America by Christopher Columbus (1451–1506), who led a Castilian (Spanish) expedition across the Atlantic, discovering America. After the discovery of America by Columbus, a number of important expeditions were sent out to explore the Western Hemisphere. This included Juan Ponce de León (1474–1521), who discovered and mapped the coast of Florida; Vasco Núñez de Balboa (c. 1475–1519), who was the first European to view the Pacific Ocean from American shores (after crossing the Isthmus of Panama) confirming that America was a separate continent from Asia; Aleixo Garcia (14?–1527), who explored the territories of present-day southern Brazil, Paraguay and Bolivia, crossing the Chaco and reaching the Andes (near Sucre).
Sebastian Cabot (explorer)
According to "Cartografía Marítima Hispana", Sebastian Cabot included a handwritten text in Latin on his famous map of North America (published in Antwerp, 1544) claiming to have discovered North America with his father in 1494, three years before his father's voyage. Sancho Gutierrez repeated this text in Castilian on his 1551 map. 
Placed next to the border of North America, the text reads:
This land was discovered by Johannes Caboto, venetian and Sebastian Caboto, his son, in the year of the birth of our Lord Jesus Christ MCCCCXCIV, 24th of June in the morning. They put to it the name 'prima terra vista' and [...] This big island was named Saint John, as it was discovered on Saint John holiday. People there wander wearing animal furs. They use bow and arrow to fight, javelins and darts and wooden batons and slings. This is a very sterile land, there are a lot of white bears and very big deers, big as horses, and many other animals. As well there are infinite fish: plaices, salmons, very long soles, 1 yard long and many other varieties of fish. Most of them are called cod. And there are also black hawks, black as ravens, eagles, partridges and many other birds.