Final answer:
Magellan faced tumultuous seas and a harsh winter at the southern tip of South America, and struggled with limited supplies. His expedition confirmed South America as separate from Asia and completed the first circumnavigation, although with heavy casualties.
Step-by-step explanation:
When Magellan reached the bottom of South America, his expedition faced harsh conditions navigating through what would later be known as the Strait of Magellan. They encountered difficult waters, storms, and spent a grueling winter in this region. The expedition confirmed Columbus's mistake and discovered that South America was a landmass separate from Asia. Magellan's fleet was vastly reduced as they faced the vastness of the Pacific Ocean and the crew struggled with limited provisions and fresh water. After crossing the Pacific, of the original 237 men and five ships that left Spain, only one ship and eighteen men returned, completing the first successful circumnavigation of the globe.